OF 

CENTER  LIBRARY 
SAN  FRANCISCO 


SURGICAL    ANATOMY 


DEAVER 


GENERAL  ARRANGEMENT  OF  CONTENTS 

VOLUME    I.  —  UPPER.    EXTREMITY — BACK    OK    NKCK —  SHOULDER —  THINK 
CRANIUM— SCALP — FACE. 

VOLUME  II. — NECK— MOUTH — PHARYNX — LARYNX— NOSE— OHBIT — EYEBAI.I.- 
ORGAN  OK  HEARING— BRAIN — FK.MAI.E  PERINEUM — MALE  PKKINEUM. 

VOLUME  III.  — ABDOMINAL  WALL  — ABDOMINAL  CAVITY  — PELVIC   CAVITY - 
CHEST — LOWER  EXTREMITY. 


SURGICAL  ANATOMY 


A  TPxEATISE  ON  HUMAN  ANATOMY 
IN  ITS  APPLICATION  TO  THE  PRAC- 
TICE OF  MEDICINE  AND  SURGERY 


BY 


JOHN    B.    DEAVER,    M.P 

SURGEOX-IN-CHIKF  TO  THK  <;ERMAX  HOSPITAL,  PHILADELPHIA 


IX  THREE  VOLUMES 

ILLVXrilATKD  II  Y  AKOUT  400  PLATES  SEA11L  Y  ALL  ]>KA\\'NFOB  77//.V   WORK 
FHHM    ORKHXAL    DIXXM'TIOXS 


VOL.  I. 


UPPER  EXTREMITY;  BACK  OF  NECK;  SHOULDER;  TRUNK; 
CRANIUM;  SCALP;  FACE 


PHILADELPHIA 
P.    BLAKISTON'S    SON    &    CO. 

1012    WALNUT    STREET 

1899 


PRESS  OF  WH.  F.  FELL  &  Co., 

1220-24  SANSOM   ST., 
PHILADELPHIA. 


.  ls',19,  BV  P.  BLAKISTOX'S  SON  >^   Co. 


TO 

Surgeons  ano  to  Stuoents   of  Surgerg  ano  Hnatomy, 

WHOSE   LABORS  IT  IS  INTENDED  TO  LIGHTEN   IN  A  FIELD  WHERE 
LABOR   ALONE    IS   THE   PRICE   OF   ATTAINMENT, 

THIS    WORK 

IS    RESPECTFULLY    DEDICATED 
BY    THEIR    FRIEND    AND    FELLOW-STUDENT 

THE     AUTHOR. 


CONTENTS  OF  VOLUME  I. 


PAGE 

UPPER  EXTREMITY, 17 

SURFACE  ANATOMY  or  THE  UPPER  EXTREMITY,      17 

THE  FOREARM  AND  WRIST, 31 

THE  HAND, 32 

NuiiVE  STRETCHING  AMI  XERVE  SECTION, 38 

DISSECTION, 47 

THE  FRONT  OF  THE  ARM, 96 

THE  FRONT  OF  THE  FOREARM, 125 

THE  FRONT  OF  THE  HAND, 152 

THE  BACK  OF  THE  ARM, 188 

THE  BACK  OF  THE  FOREARM, 195 

THE  BACK  OF  THE  HAND, 209 

JOINTS, 212 

The  Sterno-davicolar  Joint,     215 

The  Scapulo-clavicular  Joint, 221 

The  Shoulder-joint, 222 

The  Elbow-joint,      224 

Radio-ulnar  Articulations,      233 

The  Radio-carpal  Articulation, 234 

The  Carpal  Joints 238 

Carpo-metacarpal  Articulations, 242 

The  Intermetacarpal  Articulations,     245 

The  Interphalangeal  Articulations,     247 

DISLOCATIONS,     247 

ANATOMY  OF  THE  LONG  BONES, 256 

EXCISIONS, 260 

DEVELOPMENT  OF  THE  BONES, 266 

FRACTURES 269 

AMPUTATIONS,     279 

LlGATIONS  OF  THE  ARTERIES, 294 

STRETCHING  OF  THE  NERVES 311 

THE  BACK  OF  THE  NECK,  SHOULDER,  AND  TRUNK, 351 

LIGAMENTS  OF  THE  VERTEBRAL  COLUMN 412 

vii 


viii  CO.V7Vv.V7X    or    VOU'UE  I. 

PAOl 

FRACTURES  AND  DISLOCATIONS  OF  THE  YKKTKHHA, 4-24 

DISSECTION, 4:24 

THE  SPINAL  CURD, 4  IN 

SURFACE  ANATO.MV  OF  THE  CRANIUM 451 

SURFACE  ANATOMY  OF  THE  FACE 156 

SCALP 4ii:. 

FACE, 189 

PTERYGO-.MAXILI.AKY  REUIOX, 540 

THE  MEMBRANKS  AND  VKSSKI.S  OF  THE  BRAIN, '.r,s 

INTRA-CHAMAL  COI-RXE  AM.  MOLE  OF  EXIT  OF  THE  CRANIAL  NERVES, 5'.H 

INDEX.                  001 


LIST  OF  ILLUSTRATIONS. 


PLATE  I'M.I 

I.  Forearm  Pronated, 20 

II.  Forearm  Supinated,  Showing  Ulnar  Deflection, 21 

III.  Landmarks  of  Anterior  Surface 24 

IV.  Landmarks  of  Posterior  Surface, 25 

V.  Dislocated  Shoulder  and  Normal  Shoulder,     L".» 

VI.  Principal  Flexor  Furrows, :;l 

VII.  Lines  of  Arteries — Palm  of  Hand, :;."> 

VIII.  Anterior  View  of  Upper  Extremity — Motor  Points,     40 

IX.   Motor  Points  and  Lines  of  Incisions  for  Posterior  Circumflex  Artery  and  Musculo- 

spiral  Nerve 41 

X.  Dorsum  of  Scapula  Showing  Acromial  Angle, .    .  43 

XI.  Lines  of  Incisions  for  Dissection  and  J /me  for  Axillary  Artery, 45 

XII.  Superficial  Fascia  of  Pectoral  Region, 49 

XIII.  Anterior  Cutaneous  and  Lateral  Cutaneous  Nerves 52 

XIV.  Mammary  Gland,      55 

XV.   Deep  Fascia  or  Pectoral  Fascia  and  Axillary  Fascia, 5'.i 

XVI.   Diagram  of  Pectoral  Fascia  and  Axillary  Fascia. /    .    .    .    .  02 

XVII.  Pectoralis  Major  Muscle  and  PectoraEs  Minor  Muscle,     ii5 

XVIII.  Superficial  Infra-clavicular  Triangle, 70 

XIX.  Deep  Infra-clavicular  Triangle, 71 

XX.   Contents  of  Axilla  Shown  by  Dissection  Made  from  Before  Backward, 7(> 

XXI.   Contents  of  Axilla  Shown  by  Dissection  Made  from  Below  Upward, 77 

XXII.  Anastomoses  of  Arteries  Around  the  Scapula, s4 

XXIII.  Axillary  or  Brachial  Plexus  of  Nerves, S7 

XXIV.  Incisions  for  Dissection  of  Ann  and  Right  Axillary  Region, 94 

XXV.   Cutaneous  Nerves  of  Arm  and  Forearm, '.'7 

XXVI.  Superficial  Veins  of  Front  of  Arm  and  Forearm Km 

XXVII.   Superficial  Veins  of  Back  of  Forearm  and  Hand,      101 

XXVIII.  Superficial  Lymphatic  Vessels  and  Glands  of  Front  of  Upper  Extremity, 105 

XXIX.   Brachial  Artery  and  Biceps  Muscle,      IK) 

NXX.   Brachial  Artery  and  Branches Ill 

XXXI.   Biceps  Muscle, 115 

XXXII.    View  of  Arm — Biceps  Removed, 118 

XXXIII.  Lines  of  Arteries  of  Upper  Extremity  and  of  Median  and  Ulnar  Nerves, 122 

XXXIV.  Bicipital  Fascia  and  Vessels  and  Nerves  at  Elbow, 128 

XXXV.  Triangle  of  Elbow  and  Superficial  Muscles  of  Forearm, 131 

XXXVI.  Triangle  of  Elbow,  Flexor  Sublimis  Digitorum  Muscle,  Radial  Artery,  and  Radial 

Nerve, 135 

XXXVIT.   Deep  Flexor  Muscles.   Radial   Artery   and   Nerve,  Ulnar  Artery  and  Nerve,  and 

Median  Nerve, 140 

XXXVIII.  Arteries  and  Nerves  of  Front  of  Forearm, 141 

XXXIX.  Arteries  of  Forearm  and  Hand, 145 

ix 


x  LIST  01'  11. /.  I  >•  77,'.  I  770AX 

I'I.ATK  TA'.K 

XL.   Incisions  fin-  Dissei-tinn  of  Hand 150 

XLI.   Superficial  Palmar  l-'asria i:>:'} 

XLII.  Deep  Palmar  Fascia  and  Palmaris  Brevis  Muscle ].v, 

XLIII.  Superficial  Palmar  Arch  and  Di.irital  Nerves 159 

XLIV.  Arteries  and  Nerves  of  Front  of  Forearm, 163 

XLV.  Fibrous  and  Synovial  Sheaths  of  Flexor  Tendons, ir,r, 

XL VI.  Insertion  of  Lumbrical  and  Interosseous  Muscles, lo'.i 

XLVII.   Deep  Palmar  Arch  and  Interosseous  Muscles, J7:; 

XLVIII.   Lines  of  Arteries — Palm  of  Hand, 170 

XLIX.   Arteries  of  Hand,     177 

L.  Cutaneous  Nerves  of  Arm  and  Forearm, 181 

LI.  Musculo-spiral  Nerve  and  Superior  Profunda  Artery, ls4 

LII.  Muscles  of  the  Back  of  the  Scapula  and  Arm 185 

LIII.  Superficial  Veins  of  Back  of  Forearm  and  Hand 190 

LIV.  Superficial  Muscles  of  Back  of  Forearm, l'.)4 

L\'.  Deep  Muscles  of  Back  of  Forearm,  Posterior  Interosseous  Artery  and  Nerve,    .    .    .  200 

LVI.  Anterior  and  Posterior  Interosseous  Arteries, 203 

LVII.  Tendons  and  Arteries  of  Back  of  Hand, 200 

LVIII.  Sterno-clavicular  Joint — Anterior  and  Posterior  Views 214 

LIX.  Scapnlo-clavicular,  Aeromio-elavicular,  and  Scapulo-hnmeralJointa — Anterior  View.  2  Is 

LX.   Scapulo-clavicular  and  Acromio-clavicular  Joints,  and  Glenoid  Ligament, 219 

LXI.   Elbow  Joint — External  and  Internal  Views, 225 

LXII.   Interior  Iladio-ulimr  Joint — Anterior  View, 230 

LXIII.  Inferior    Radio-ulnar,    Radio-carpal,    Intercarpal,    and    Carpo-metacarpal  Joints- 
Posterior  View, 231 

LXIV.   Inferior    Radio-ulnar,    Radio-carpal,    Intercarpal,    and    Carpo-metacarpal    Joints — 

Anterior  View 2:;:> 

LXV.   Section  of  Joints  of  Wrist  and  Hand, 239 

LXVI.  Metaoarpo-phalangeal  and  Interphalangeal  Ligaments  (Middle  Finger), 244 

LXVII.  Dislocated  Shoulder  and  Normal  Shoulder,     249 

LXVI  1 1.   Skiagraph  of  Fetal  Skeleton.     By  M.  I.  Wilbert 257 

LXIX.  Displacement  in  Fracture  of  the  Middle  of  the  Clavicle,      20S 

Fracture  of  Anatomical  Neck  of  Scapula, 2(iS 

LXX.  Fracture  Through  Surgical  Neck, 272 

Fracture  Above  Insertion  of  Deltoid  Muscle 272 

LXXI.  Fracture  Below  Insertion  of  Deltoid  Muscle 270 

Colics'  1'Yacture,     . 270 

LXXII.   Transverse  Section  of  Forearm  Just  Below  Middle, 280 

LXXI  11.   Transverse  .Section  of  Arm  Below  Insertion  of  Deltoid  Muscle, 290 

LXXIV.  Transverse  Section  of  Arm  Above  Cundyles  of  Humerus, 2U1 

LXXV.  Aneurysmal  Varix  ;  Varicose  Aiieurysin  ;  Method  of  Antyllus  ;  Hunter's  Method  ; 

Brasdor's  Method  ;  Wardrop's  Method 295 

LXXVI.  Lines  of  Arteries  of  Upper  Extremity  and  of  Median  and  Ulnar  Nerves, 300 

LXXVII.  Lines  of  Incisions  for  Ligation  of  Arteries  and  Stretching  of  Nerves, 301 

LXXVIII.  Operations  for  Exposure  of  Third  Part,  Axillary  Artery,  and  Large  Branches  of 
Brachial,  Brachial  Artery  and  Median  Nerve  at  Middle  of  Arm,  and  Ulnar  Nerve 

in  Lower  Half  of  Arm, 316 

LXXIX.   Axillary  Artery  and  Large  Branches  of  Brachial  I'lexus — Third  Portion, 317 

LXXX.  Brachial  Artery  and  Median  Nerve  at  Middle  of  Arm, 319 

LXXXI.   Ulnar  Nerve  in  Lower  Half  of  Arm 321 

LXXXIt.  Diagram  of  Collateral  Circulation,      324 

I, XXXIII.  Diagram  of  Collateral  Circulation, * 325 

LXXXIV.  Brachial  Artery  and  Median  Nerve  at  Elbow,  Radial  Artery  and  Radial  Nerve  at 
Middle  of  Forearm,  Radial  Artery  in  Lower  Third  of  Forearm,  and  Ulnar  Artery 

and  Nerve  Above  Wrist,      328 


LIST  OF  ILLUSTRATIONS.  xi 

PLATE 

LXXXV.   Brachial  Artery  ami  Median  Nerve  at  Elbow,      329 

LXXXVI.   Eladial  Artery  and  Nerve  at  Middle  of  Foreann, 331 

LXXXVII.   Radial  Artery  Above  Wrist, 333 

LXXXVIII.  Ulnar  Artery  and  Ulnar  Nerve  Above  Wrist, (35 

LXXXIX.  Incision  for  Radial  Artery  in  "Snuff'-box,"'      337 

XC.    Radial  Artery  in   "  Snuff-box," 339 

XCI.  Posterior  Circumflex  Artery  and  Circumflex  Nerve, :;il 

XCII.  Subscapular  Artery,  Middle  and  Lower  Subscapular  Nerves, 343 

XCIII.   Musculo-spiral  Nerve  Above  External  Condyle  of  Humerus, 345 

XCIV.  Musculo-apiral  Nerve  Above  External  Condyle  of  Humerus 347 

XCV.   Median  Nerve  Almve  Wrist, 349 

XCVI.   Surface  .Marks  of  Back, 353 

XCVII.  Lordosis ;  Normal  Curve ;  Kyphosis;  Lateral  Curvature, 358 

XCVIII.   Early  Lumbar  Caries,  Normal  Curve  Effaced  ;  Normal  Curve  ;  Advanced  Dorsi- 

lumbar  Caries,  Angular  Curvature 359 

XCIX.  Relation  of  Viscera  of  Thorax  and  Abdomen  to  Bony  Prominences  of  Back,    .   .    .  363 

C.  Incisions  for  Dissection, 305 

CI.   Cutaneous  Nerves  of  Back,      :;r,',t 

CII.    Muscles  nl'  Back 373 

CIII.  Post-scapular  Muscles  and  Triceps  Muscle, :;>i 

CIV.  Anastomoses  of  Arteries  Around  the  Scapula, 385 

CV.   Subseapularis  Muscle  and  Subscapular  Triangle,      390 

CVI.  Serratufi  Magnus  Muscle,     391 

CVII.   Muscles  of  Back 396 

CVIII.   Deep  Muscles  of  Back 397 

CIX.   Suboccipital  Triangle, 40C, 

CX.  Ligaments  of  Spinal  Column, 4];>, 

CXI.   Occipito-atlantal  and  Atlanto-axuiilean  Ligaments — Anterior  and  Posterior  Views,  .  417 

CXII.  Lmanients  in  Posterior  Surface  of  Upper  Part  of  Anterior  Wall  of  Spinal  Canal,     .  421 

Central  Atlanto-axoiil  Joint 42] 

CXIII.   Spinal  Veins, 4^;, 

CXIV.  Spinal  Cord  and  Membranes, 4^<i 

CXV.  Cauda  Equina, 433 

CXVI.  Sections  of  Spinal  Cord  (W.  R.  Gowere),     437 

CXVII.   Spinal  Cord, 4:;'J 

CXV1II.   Nerve-tracts  of  Spinal  Cord, 441 

CXIX.   Approximate  Relation  to  tile  Spinal   Xerves  of  the  Various  Motor,  Sensory,  and 

Reflex  Functions  of  the  Spinal  Cord  (Gowers), 447 

CXX.  Cranial  Landmarks  and  Lines  of  Cerebral  Fissures A:t:>, 

CXXI.  Incisions  for  Dissection, 4ti] 

CXX1I.   Layers  of  Scalp, 463 

Cirsoid  Aneurysm,     4(53 

CXXIII.  Superficial  Fascia  of  Scalp, 467 

CXXIV.  Arteries  of  Scalp  and  Face 472 

CXXV.   Nerves  of  Scalp  and  Facial  NeiTe, 473 

CXXVI.  Arteries,  Nerves,  and  Muscles  of  Scalp  and  Face, 477 

CXXVII.  Temporal  Fascia  and  Nerves  of  Face, 484 

CXXVIII.  Temporal  Muscle 485 

CXXIX.   Incisions  for  Dissection  and  Lines  for  Vessels  and  Nerves  of  Face 487 

CXXX.  Muscles  of  Face  and  Scalp,      4yi 

CXXXI.  Tensor  Tarsi  and  Oorrugator  Supercilii  Muscles,      496 

CXXXII.  Arteries  of  Scalp  and  Face, 504 

CXXXIII.   Arteries,  Nerves,  and  Muscles  of  Seal])  and  Face, 505 

CXXXIV.  Veins  of  Scalp,  Face,  and  Neck, 509 

CXXXV.  Palpebral  Fissure  and  Eyeball— Eyelids  Everted, 513 


xii  L1XT  OF  ILLUSTRATION. 

PAQB 

CXXXVf.   Lacrymal  Apparatus  and  Meibomian  (Hands ,r)17 

( 'XXX  VII.   Pinna, 525 

CXXXVIII.    Intrinsic  Muscles  of  Pinna 527 

CXXXIX.   Norves  of  Scalp  and  Facial  Nerve,      531 

CXI/.   Operation  for  Exposure  of  Facial  Nerve,      iVlii 

CXLI.   Temporal  Fascia  and  Xorvos  of  Face f).",7 

CXLII.   Pterygoid  Musi-les  and  Internal  Maxillary  Artery, ">42 

CXI, II  I.  [nternal  Maxillary  Artery  and  Branches 54(i 

CXLIV.   Inferior  Maxillary  Xerve 550 

CXLV.   Olfactory  Nervos  ami  Internal  View  of  the  Spbeno-palatine  and  ( (tie  (lanulia,    .    .  554 

CXLVf.  Superior  and  Inferior  Maxillary  Nerves 559 

CXLVII.    Diploic-  Veins S(V.» 

CXLVI1I.    Pnra  Mater,  Arachnoid,  and  MeniiiL'eal  X'essels, :"i7.'> 

CXLIX.    Sinuses  and  Prore.-se-  of   I'lira  Mater 57S 

CL.   Sinuses  and  Cranial  Nerves 579 

CLI.  Lines  for  Sinuses, 585 


PREFACE. 


This  book  has  been  twelve  years  in  preparation.  During  this  time,  while1  no 
change  has  been  made  in  its  plan,  its  scope  has  been  much  enlarged,  to  meet  a 
wider  field  than  for  which  it  wa.s  first  intended.  My  original  purpose  was  to 
furnish  for  students  a  text-book  of  Surgical  Anatomy,  then  much  needed  and  not 
obtainable  by  them.  1  have  made  a  book  which  will  be  serviceable,  I  hope,  not 
alone  to  them,  but  to  practising  physicians  and  surgeons.  While,  I  regret  to  sav, 
this  subject  is  much  neglected  in  our  American  institutions,  there  came  to  be, 
nevertheless,  during  the  progress  of  this  work,  an  increasing  and  encouraging 
recognition  of  its  importance.  In  some  schools  the  course  was  much  enlarged  ;  in 
others  new  courses  were  established.  In  my  own  classes  the  work  has  constantly 
grown,  until  it  has  become  not  alone  an  adjunct  to,  and  application  of,  descriptive 
anatomy,  but  rather  the  bridge  bet  ween  that  study  and  practice  of  surgery  itself.  To 
meet  these  requirements  it  has  not  been  sufficient  for  me  to  emphasize  and  clarify 
the  facts  of  descriptive  anatomy  as  required  of  undergraduates.  I  have  been 
compelled  to  bring  to  them  the  knowledge  of  anatomy  which  I  have  used  and  as 
I  have  used  it  in  surgical  practice. 

My  book  has  kept  pace  with  this  change  and  growth.  I  have  in  no  case 
cut  down  descriptions  nor  the  teaching  devoted  to  surgical  anatomy,  nor  directions 
for  and  procedure  in  dissection,  but  I  have  added  much  relating  to  surgical  work. 
I  have  endeavored  to  regard  fully  the  necessities  of  undergraduates,  and  at  the 
same  time  have  had  in  mind  constantly  the  requirements  which  they  will  meet 
as  surgeons  in  their  chosen  field,  and  have  tried  to  make  for  them  a  sufficient  work 
of  reference  for  use  in  actual  practice. 

I  am  aware  that  much  of  the  ground,  particularly  that  portion  relating 
to  regional  anatomy,  has  been  covered  by  other  books.  The  valuable  works 
of  Cunningham,  McLaughlin,  Holden,  Treves,  Heath,  Owen,  and  others,  the 
companions  and  guides  of  many  years,  have  been  at  my  hand  for  constant  refer- 
ence. I  welcome  this  opportunity  to  acknowledge  my  great  indebtedness  to  them. 

I  have  hoped,  gathering  freely  from  every  source,  adding  much  from  surgical 

xiii 


xv 


cx|icrience,  and  arranging  the  whole  as  systematically  as  possible.  In  make  for  tlie 
student  and  practical  doctor  a  work  of  reference  which  is.  comparatively  speaking. 
complete. 

The  illustrations  have  been  for  the  most  part  made  from  dissections,  and  are, 
therefore,  original  and  accurate.  Too  much  praise  can  not  lie  given  the  artists 
and  engravers  who  have  expended  in  their  production  infinite  care  and  an  interest 
which  has  been  most  conscientious.  I  believe  that  vise  Avill  lead  to  appreciation  of 
the  great  value  of  their  labors. 

I  take  this  opportunity  to  thank,  and  acknowledge  the  services  of.  Or.  Carl 
Ilamann,  my  old  student  and  house  surgeon,  now  Professor  of  Anatomy  in 
the  Western  Reserve  University,  Cleveland.  Ohio,  for  reading  the  manuscript; 
Dr.  J.  Rex  Hobeusack,  formerly  my  prosector  in  the  University  of  Pennsyl- 
vania, for  the  excellent  dissections  from  which  the  illustrations  were  made  and 
for  other  valuable  services  in  the  preparation  of  this  book,  and  Dr.  A.  1).  Whiting, 
for  making  the  index. 

1034  WALNUT  STREET, 
PHILADELPHIA. 


SURGICAL    ANATOMY. 


UPPER   EXTREMITY. 

SURFACE  AXATOM}'   <)!•    Till'.    l'I'l'l-:i!    KX'HIKMITY. 

Divisions. — Tin-  upper  extremity  is  divisible  into  the  shoulder,  tht.1  urni. 
the  forearm,  the  wrist,  and  the  hand. 

The  Articulations  to  he  studied  are  the  xlimilili'i- .-  the  ilium-;  the  xiijH-ri'ti' 
and  iuj'i-i'ini-  r/iilin-iiliiiir :  the  rinlin-i-iii-jiii/.  or  irrixt  :  the  coppo-metacarpal ;  the 
mihu-iir/iii-jiliii/iiiii/i'ii/.  of  which  there  are  live;  and  the  jil«t/<ni//<'<il,  of  which 
there  are  nine. 

The  various  Movements  should  he  home  in  mind.  The  upper  extremity, 
as  a  whole,  can  he  rotated  on  its  axis  at  the  shoulder-joint,  so  great  freedom  being 
provided  that  any  part  of  the  hody  can  he  touched  by  one  or  the  other  hand. 
At  the  elhow  the  movements  are  flexion  and  extension;  the  former  is  limited  by 
the  contact  of  the  forearm  with  the  arm,  and  the  latter  hy  the  contact  of  the 
olecranon  process  of  the  ulna  with  the  humerus.  Through  the  radio-ulnar 
articulations  the  forearm  is  supinated  and  pronated.  and  extreme  pronation  and 
stipulation  are  permitted  hy  rotation  of  the  humerus.  Through  the  radio-carpal,  or 
wrist,  articulation  the  hand  is  Hexed  and  extended  on  the  forearm.  The  meta- 
carpo-phalangeal  and  inter-phalangeaJ  articulations  provide  for  the  opening  and 
closing  of  the  fist  and  the  spreading  of  the  lingers. 

If  the  forearm  he  supinated  and  in  the  extended  position,  it  will  he  noticed 
that  a  line  drawn  in  the  long  axis  of  the  arm  will  form  at  the  elhow  an  obtuse 
angle,  with  a  line  drawn  in  the  long  axis  of  the  forearm.  The  opening  of  the 
angle  is  directed  outward.  (Plate  II.)  This  difference  in  direction  is  known  as  the 
ii/iiar  deflection,  and  should  he  carefully  noted,  as  it  is  of  importance  in  the  treat- 
ment of  fractures  at  or  near  'the  elhow-joint,  The  strength  of  the  arm  and  its 
adaptability  to  various  functions  depend  to  some  extent  upon  the  maintenance  of 
this  angle.  With  the  forearm  extended  and  midway  between  pronation  and 
2  17 


IX  SURGICAL    A  ^  ATOMY. 

snpination,  the  lines  are  practically  parallel  :  while   in  extreme  pronation.  the  lines 
i'nnn   an  obtuse  angle,  the  opening  of  which  is  ilirected  inward  instead  of  outward. 

Surface  Markings. — l.el'ore  commencing  the  dissection  of  the  upper  ex- 
tremity the  surface  markings  should  he  studied.  The  clavicle  is  readily  felt, 
even  in  the  stouteM  persons.  It  is  convex  forward  at  its  inner  two-thirds,  and 
concave  forward  at  its  outer  one-third.  The  clavicle  has  a  slightly  downward  -slope 
when  the  hody  is  in  the  upright  position  and  with  the  arm  at  the  side;  hut  it  is  a 
little  raised  when  the  hody  is  in  the  supine  position.  Advantage  is  taken  of  these 
facts  in  the  reduction  and  treatment  of  fractures  and  dislocations  of  the  clavicle. 
It-  articulation  with  the-  sternum  is  easily  felt,  while  that  with  the  acromioii  proce>s 
of  the  scapula,  forming  the  hony  arch  of  the  shoulder,  is  not  so  easily  distin- 
guished. This  prominence,  formed  by  the  hony  arch  of  the  shoulder,  must  not  he 
confounded  with  the  roundness  of  the  shoulder,  which  is  occasioned  by  the  threat er 
tuberosity  and  head  of  the  humerus  and  the  superimposed  deltoid  muscle.  After 
amputation  at  the  shoulder-joint  the  prominence  of  the  shoulder  remains,  but  the 
roundness  is  lost,  owing  to  the  removal  of  the  upper  end  of  the  humerus.  The 
relation  of  these  bony  points  is  important  in  the  diagnosis  of  dislocations  of  the 
head  of  the  humerus.  A  "deltoid  tubercle"  is  sometimes  present  at  the  outer 
one-third  of  the  clavicle,  and  must  not  lie  mistaken  for  an  exostosis. 

The    infra-clavicular   fossa. — This  is  a   depression  seen  immediately  below 
the  middle  of  the  clavicle,  and  corresponds  to  the   interval   between  the  origins  ol 
the    pectoral  is    major    and    deltoid   muscles.      It    is   less  evident    in    muscular  per- 
sons than  in  those  not  so  well  developed. 

The  coracoid  process  does  not  give  rise  to  any  visible  external  eminence, 
except  in  very  thin  persons,  but  can  be  palpated  by  introducing  the  finger  into 
the  infra-clavicular  fossa  and  displacing  the  anterior  border  of  the  deltoid  upward 
and  outward. 

The  acromion  process  and  the  spine  of  the  scapula  are  subcutaneous  and  very 
prominent.  The  acromion  may  consist  of  one  or  two  separate  pieces  which  have 
failed  to  co-ossify  with  the  spine  of  the  scapula  ;  so  that  there  may  be  one  or  two 
epiphyses,  which,  if  incompletely  united  with  the  rest  of  the  bone, might  be  mis- 
taken for  fragments  of  a  fractured  acromion.  The  cpiphyscs.  if  present,  will  be 
found  on  both  sides,  while  it  would  be  rare  to  find  a  fracture  on  more  than  one 
side.  Tin'  angle  formed  by  the  acromion  process  and  the  spine  of  the  scapula  is 
readily  made  out,  and  affords  a  convenient  point  from  which  to  measure  in  com- 
paring the  lengths  of  the  arms.  In  taking  these  measurements,  the  lower  points 
selected  are  the  external  condyle  of  the  humerus  and  the  tip  of  the  styloid  process 
of  the  radius.  The  two  arms  should,  it  is  needless  to  mention,  be  placed  in  the 
same  position. 


PLATE  I. 


UPPER  EXTREMITY- FOREARM  PRONATED. 
20 


PLATE  II 


UPPER  EXTREMITY- FOREARM  SUPINATED,  SHOWING  ULNAR  DEFLECTION. 

21 


PLATE 


UPPER  EXTREMITY- LANDMARKS  OF  ANTERIOR  SURFACE. 
24 


PLATE 


—  Dimple  over  head  of  radius 


Subcutaneous  portion  of  ulna 


UPPER  EXTREMITY-LANDMARKS  OF  POSTERIOR  SURFACE. 
25 


SURFACE  ANATOMY  <>b'  THE  ri'l'Ki;    EXTREMITY.  '11 

The  biceps  muscle  stands  out  as  a  well-rounded  prominence  mi  the  anterior 
surface  <>!'  the  aria.  It  is  limited  <>n  cadi  side  by  a  more  or  less  well-marked 
groove.  The  internal  groove  contains  the  principal  vessels  and  nerves  of  the  arm  : 
the  outer,  the  cephalic  vein. 

The  deltoid  muscle  can  he  easily  recognized  covering  the  greater  tuherosity 
of  the  humerus.  Paralysis  and  subsequent  atrophy  of  this  muscle  will  cause  part 
(if  the  roundness  of  the  shoulder  to  disappear.  Through  this  muscle  the  greater 
tuherosity  of  the  humerns  can  he  distinctly  felt.  The  prominence  immediately 
helow  the  aeroimou.  anil  felt  most  plainly  if  the  arm  he  rotated  on  its  long  axis, 
is  the  greater  tuherosity.  To  the  inner  side  of  and  a  little  helow  the  greater,  the 
lesser  luherosity  can  he  felt.  By  making  pressure  in  a  vertical  line  between  these 
two  prominences,  the  arm  being  rotated  outward  and  hanging  at  the  side,  the 
bieipital  groove,  which  accommodates  the  long  tendon  of  the  biceps,  can  be  felt. 
In  dislocation  of  this  tendon — which,  however,  is  quite  rare — the  groove  becomes 
much  more  perceptible  to  the  sense  of  touch. 

The  head  of  the  humerus  is  most  readily  felt  by  inserting  the  fingers  into  the 
axilla.  In  subgleiioid  dislocation  of  the  head  it  will  be  felt  in  the  axilla  as  a 
very  prominent  mass. 

The  coraco-acromial  ligament  is  distinctly  felt  tinder  the  anterior  fibers  of  the 
deltoid.  The  midpoint  of  this  ligament  corresponds  to  the  site  of  the  bieipital 
groove  and  the  long  tendon  of  the  biceps. 

The  course  of  the  axillary  artery,  with  the  arm  at  a  right  angle  to  the 
bodv,  is  indicated  by  a  line  extending  from  a  point  slightly  to  the  inner  side  of 
the  middle  of  the  clavicle  to  the  middle  of  the  bend  of  the  elbow. 

The  axilla. — The  lower  margin  of  the  anterior  wall  of  the  axilla  (the  lower 
border  of  the  pectoralis  major)  follows  the  fifth  rib.  Normally,  the  glands  of  the 
axilla  are  not  palpable.  The  skin  of  the  floor  of  the  axilla  is  covered  by  an 
elongated  patch  of  hair.  In  the  skin  and  superficial  fascia  of  the  floor  of  the  axilla, 
are  modified  sebaceous  and  sweat  glands.  These,  especially  the  sebaceous  glands, 
not  infrequently  become  infected,  when,  if  not  treated  antiseptic-ally,  they  mav 
infect  the  glands  of  the  axilla.  These  glands  are  occasionally  the  site  of  primary 
malignant  disease.  An  abscess  of  the  axilla  should  be  opened  midway  between 
the  anterior  and  posterior  walls,  the  incision  being  carried  from  the  arm  toward 
the  chest  to  avoid  injuring  the  large  vessels  which  course  along  the  outer  wall. 

The  course  of  the  vessels  and  nerves  of  the  arm,  as  in  other  parts  of  the 
body,  is  along  protected  routes.  They  pass  from  the  axilla  along  the  inner  side  of 
the  arm.  thence  in  front  of  the  elbow,  and  between  the  muscles  of  the  upper  fore- 
arm. In  the  lower  third  of  the  forearm  they  lie  near  the  surface,  between  the 
flexor  tendons.  Upon  the  digits  they  lie  on  the  sides,  where  they  are  more  pro- 


•js  SURGICAL    .\\ATOMY. 

i' •ctcd.  The  veins,  injury  of  which  is  less  dangerous  than  that  of  either  tlie  arteries 
or  tlie  nerves,  are  inure  superficial. 

The  deep  and  the  superficial  veins  communicate  freely  at  the  joints,  thus 
insuring  a  free  and  uninterrupted  return  circulation  during  strong  and  continuous 
muscular  contraction.  They  have  a  larger  total  capacity  than  the  arteries,  and 
this  alone  is  ample  reason  for  the  slower  How  of  the  venous  current.  They  contain 
numerous  valves,  which  are  necessary  on  account  of  the  deficient  contractile 
power  of  the  veins.  The  Mood  in  them  can  not  recede,  liecause  of  the  closing 
of  the  valves,  which  hold  it  in  lock  until  extraneous  muscular  contraction  or 
cardiac  and  vasomotor  vis  a  tergo  push  the  contained  Mood  forward;  or  until 
a  change  of  position  favors  the  descent  of  the  Mood  by  gravity.  The  promptness 
with  which  the  veins  are  emptied  by  gravity  is  quickly  and  easily  demonstrated 
by  the  simple  experiment  of  holding  one  hand  over  the  head  while  the  other 
hangs  loosely  at  the  side.  If,  after  remaining  in  this  position  for  ahout  one-half 
of  a  minute,  the  hands  are  brought  together  in  front,  the  previously  uplifted 
one  will  appear  bloodless  while  the  other  will  show  well-tilled  vessels. 

The  course  of  the  brachial  artery,  with  the  arm  at  a  right  angle  to  the 
body,  corresponds  to  a  line  extending  from  a  little  to  the  inner  side  of  ihe 
middle  of  the  clavicle  to  the  middle  of  the  bend  of  the  elbow.  The  artery 
is  overlapped  by  the  inner  edge  of  the  biceps  muscle.  It  is  readily  reached  in 
any  part  of  its  course,  and  is  easily  compressed  at  its  middle,  where  it  lies  upon 
the  insertion  of  the  coraco-brachialis,  opposite  the  insertion  of  the  deltoid. 

The  dimple  behind  the  elbow,  so  much  admired  in  a  well-rounded  forearm, 
and  so  evident  in  children,  who  are  generally  well  supplied  with  fat,  is  the  depres- 
sion below  the  outer  humeral  condyle.  It  indicates  the  position  of  the  head  of  the 
radius,  which  can  hi'  felt  rotating  when  the  arm  is  alternately  pronated  and  supin- 
ated.  In  thin  persons,  and  on  the  back  of  the  forearm  while  in  extreme  pnmation, 
the  bicipital  tuberosity  of  the  radius  can  be  felt  below  the  head  of  the  radius. 

The  supra-condyloid  process  is  a  hook-shaped  splenic  of  bone  which  occasion- 
ally projects  from  above  the  inner  condyle  of  the  humerus.  It  often  gives  origin  to 
a  third  head  of  the  pronator  radii  teres  muscle,  which  covers  the  brachial  artery. 
This  process  must  not  he  mistaken  for  an  exostosis  ;  it  is  the  rudiment  of  a  process 
of  hone  which  forms  the  supra-condyloid  foramen  in  some  of  the  mammalia.  In 
these  animals  the  foramen  transmits  the  brachial  artery  and  the  median  nerve. 

Bursaeare  present  over  the  olecranon,  the  baek  of  the  upper  end  of  the  ulna, 
and  each  condyle. 

The  condyles  and  olecranon. — The  bony  prominences  at  the  elbow  are 
important  in  the  diagnosis  of  fractures  and  dislocations  occurring  in  this  locality. 
These  prominences  are  the  internal  and  external  condyles  of  the  humerus  and  the 


PLATF.  V. 


^vl" 


DISLOCATED  SHOULDER  AND  NORMAL  SHOULDER 
29 


SURFACE   .\.\ATOMY   OF   THE   ('/'PER   EXTHEMITr.  :!1 

olecranon  process  of  the  ulna.     In  their  normal  condition,  with  the  forearm  fully 

extended,  tin-  tij)  of  the  olecranon  and  the  two  condylcs  lie  in  the  same  transverse 
line.  If  the  forearm  he  Hexed,  the  oleeranon  process  will  lie  helow  a  line  drawn 
from  one  condyle  to  the  other.  The  vertical  limits  of  the  elbow-joint  are  indi- 
cated above  by  an  intercondyloid  line;  below,  by  the  lowest  part  of  the  head  of 
the  radius. 

Extreme  elbow  llexion  arrests  the  flow  of  blood  in  the  braehial  artery  below 
this  joint. 

THE   FOREARM   AND    WRIST. 

The  ulna  is  subcutaneous  along  its  posterior  border  throughout  its  entire 
length,  when  the  forearm  is  supinated,  hut,  in  pronation,  the  muscles  of  the  back 
of  the  forearm  overlap  the  ulna  and  obscure  it.  Irregularities  of  the  posterior 
border  of  the  shaft  are,  therefore,  very  readily  detected  during  snpination. 

The  radius  is  so  enveloped  by  muscle  in  its  upper  half  that,  with  the  exception 
of  its  head,  it  is  beyond  reach;  but  in  its  lower  part  it  is  quite  accessible,  being 
even  subcutaneous  at  its  lower  end.  The  lower  end  of  the  radius  extends  further 
downward  and  forward  than  does  that  of  the  ulna. 

The  course  of  the  radial  artery  corresponds  to  a  line  extending  from  the 
middle  of  the  bend  of  the  elbow  to  the  inner  side  of  Ihe  base  of  the  styloid  process 
of  the  radius.  The  artery  is  overlapped  in  its  upper  one-ln/If  by  the  snpinator 
longus  muscle.  To  reach  it  at  this  part  of  its  course  it  is  therefore  necessary  to 
displace  the  inner  edge  of  this  muscle  outward. 

The  ulnar  artery  takes  a  curved  course,  which  may  be  represented  by  two 
lines:  The  line  for  the  upper  one-third  of  the  artery  is  drawn  from  a  point  one- 
half  of  an  inch  below  the  middle  of  the  bend  of  the  elbow  to  the  inner  border 
of  the  forearm  at  the  junction  of  its  upper  with  its  middle  one-third  ;  the  line 
for  the  lower  two-thirds  of  the  artery  is  drawn  from  midway  between  the  internal 
eondyle  and  the  middle  of  the  bend  of  the  elbow  to  the  radial  side  of  the 
pisiform  bone.  In  consequence  of  the  superficial  location  of  the  arteries  of  the 
upper  limb,  and  their  occasional  anomalous  course,  their  exact  position  should 
be  ascertained  by  digital  palpation  before  the  skin  is  incised. 

Study  of  the  front  of  the  carpus  reveals  the  following  points  :  The  tubercle 
of  the  scaphoid,  below  the  styloid  process  of  the  radius  and  to  the  inner  side  of  the 
thumb  extensors ;  the  trapezium,  a  little  below  the  tubercle  of  the  scaphoid;  the 
pisiform  bone,  just  below  the  ulna  011  the  palmar  surface,  at  the  base  of  the  hypoth- 
enar  eminence ;  the  cuneiform  bone,  upon  the  inner  side  of  the  pisiform ;  several 
transverse  furrows  in  front  of  the  wrist,  the  lowest  of  which  marks  the  upper  edge 
of  the  anterior  annular  ligament  and  the  line  of  the  intercarpal  joint;  the 


:\-2  SURGICAL   AXATO.MY. 

tendons,  when  the  wrist  is  flexed  :  the  pulsation  of  the  radial  artery  where  it 
lies  on  the  outer  side  of  the  llexor  tendons  (between  the  tendons  of  the  snpinator 
longus  and  flexor  carpi  radialis) ;  the  tendon  of  the  flexor  carpi  ulnaris.  \vhieh 
overlaps  the  nlnar  artery,  thus  masking  its  pulsation.  The  level  of  the  radio- 
earpal,  or  wriM.  joint  eorresponds  to  the  interval  hetween  the  styloid  process  of  the 
radius  and  the  tubercle  of  the  scaphoid.  Incision-  into  the  front  of  the  wrist  for 
the  evacuation  of  pus  should  he  made  upon  the  ulnar  side  of  the  llexor  carpi 
radialis  tendon,  and  rather  close  to  it,  so  as  to  avoid  the  radial  artery,  externally, 
and  the  median  nerve  internally,  which  lies  a  little  to  the  ulnar  side  of  this 
tendon.  Too  deep  an  incision  may  enter  the  flexor  sheath  or  great  carpal  hnrsa. 

The  pulse. — The  pulsation  of  the  radial  artery  in  front  of  the  lower  end  of 
the  radius,  upon  the  radial  side  of  the  flexor  carpi  radialis  tendon,  is  commonly 
known  as  the  "  pulse."  Sometimes  the  superficialis  vohe  arises  high  up  and 
descends  with  the  radial,  thus  giving  the  impression  of  a  donhle  pulse  (pulsus 
duplex).  At  other  times  the  radial  artery  turns  backward  over  the  radius  higher 
up  than  usual,  and  then  the-  pulse  is  not  found  in  its  normal  position. 

"The  anatomic  snuff-box"  is  a  designation  given  by  the  French  to  the  space 
upon  the  radial  side  of  the  hack  of  the  wrist  hetween  the  iirst  and  second  tlmmh 
extensor-!.  It  is  hounded  ahove  hy  the  styloid  process  of  the  radius,  helow  hy  the 
base  of  the  metacarpal  hone  of  the  thumb,  upon  the  radial  side  by  tin1  tendons  of 
the  extensor  ossis  metacarpi  pollicis  and  extensor  primi  internodii  pollicis,  and 
upon  the  ulnar  side  by  the  tendon  of  the  extensor  secundi  internodii  pollicis.  In 
it  are  found  the  superficial  radial  vein  ;  the  radial  artery,  as  it  dips  forward  into 
the  first  interosseous  space  to  form  the  deep  palmar  arch  ;  and  the  base  of  the  first 
metacarpal  bone.  The  artery  gives  off  in  this  space  the  posterior  carpal,  the  iirst 
dorsal  interosseou-.  the  dor-ales  pollicis.  and  the  dorsalis  indicis  artery. 

"  Tenalgia  crepitans  "  is  the  name  given  to  a  grating  sensation  present  at 
the  back  of  the  wrist  in  synovitis  of  the  sheaths  of  the  extensor  tendons  of  the 
fingers — thecitis — and  in  the  dryness  accompanying  uric  acid  disease. 


THK    HAND. 

The  palm  of  the  hand  presents  two  eminences,  a  depression,  and  three  furrows. 
The  eminences  are  the  thenar — the  ball  of  the  thumb — and  the  hypothenar.  The 
thenar  eminence  is  produced  hy  the  short  muscles  of  the  thumb,  and  the  hypoth- 
enar  eminence  by  the  short  muscles  of  the  little1  finger.  The  thenar  eminence  is 
situated  at  the  base  of  the  thumb,  and  the  hypothcnar  at  the  base  of  the  little  finger. 
The  depression  of  the  palm  or  hollow  of  the  hand  is  triangular  in  shape.  The  ba>e 
of  the  triangle  is  formed  by  the  elevations  at  the  roots  of  the  lingers,  the  sides  by  the 


PLATE 


PRINCIPAL  FLEXOR  FURROWS. 
34 


PLATE  VII, 


Radial  a. 


Superficial  volae  a. 


Pnnceps  pollicis  a. 


Radialis  indicis  a. 


Digital  a. 


Interosseous  a. 


Ulnar  a. 


Deep  branch  of  ulnar  a. 


Deep  palmar  arch 
Line  for  deep  palmar  arch 

Superficial  palmar  arch 

—  Line  for  superficial 
palrhar  arch 


PALM  OF  HAND -LINES  OF  ARTERIES, 
35 


SURFACE  AXATOMY   OF   THE   I'lTER   EXTREMITY.  37 

thenar  and    hypothenar  eminences,  and  the  apex  by  the  junction  of  the  thenar 
and  hypothenar  eminences. 

The  palmar  flexor  furrow  is  composed  of  two  parts,  an  ulnar  and  a  radial. 
The  ulnar  part  (convex  upward)  extends  from  in  front  of  the  head  of  the  fifth  ineta- 
carpal  bone  to  the  web  between  the  index  and  middle  ringers,  and  the  radial  part 
(convex  downward)  extends  from  in  front  of  the  head  of  the  inetaearpal  bone  of  the 
index  finger  to  the  hypothenar  eminence.  When  the  fingers  are  flexed,  the  trans- 
verse portions  of  these  furrows  form  a  deep  fissure  with  a  central  interruption. 
This  fissure  indicates  the  position  of  the  heads  of  the  mctacarpal  bones ;  the  upper 
limits  of  the  synovial  sheaths  of  the  flexor  tendons  of  the  index,  middle,  and  ring 
lingers:  the  division  of  the  palmar  fascia  into  four  slips,  and  the  transverse  meta- 
carpal  ligament;  while  a  little  below  it  the  digital  arteries  bifurcate  into  their 
terminal  branches.  An  arched  furrow  also  extends  around  the  base  of  the  thenar 
eminence  from  the  outer  end  of  the  radial  portion  of  the  palmar  flexor  furrow  to 
the  base  of  the  thenar  eminence.  It  is  placed  opposite  the  carpo-metacarpal  joint 
of  the  thumb;  this  relation  is  analogous  to  that  of  the  other  two  furrows  to  the 
metacarpo-phalangeal  joints.  If  the  meta carpal  bone  of  the  thumb  be  viewed  as 
the  first  phalanx, — which  it  is  from  a  developmental  point  of  view, — the  analogy  is 
more  complete,  all  three  furrows  marking  the  position  of  the  basal  articulations 
of  the  primary  phalanges. 

On  the  palmar  surface  of  the  finger  there  are  three  transverse  furrows; 
the  last  two  locate  the  position  of  the  interphalangeal  joints,  the  first  furrow 
being  nearly  midway  between  the  metacarpo-phalangeal  and  the  first  inter- 
phalangeal articulations. 

With  the  thumb  strongly  abducted,  a  line  drawn  from  its  lower  border  trans- 
versely across  the  palm  of  the  hand  represents,  for  all  practical  purposes,  the  lowest 
point  in  the  course  of  the  superficial  palmar  arch.  A  line  drawn  one-half  of  an 
inch  to  the  proximal  side  of  that  for  the  superficial  arch,  and  parallel  to  it,  repre- 
sents the  course  of  the  deep  arch. 

The  interosseous  arteries,  both  dorsal  and  palmar,  run  along  the  interosseous 
spaces,  thus  making  it  desirable  when  opening  abscesses  of  either  the  front  or 
back  of.  the  hand  to  carry  the  incision  over  the  inetaearpal  bones  rather  than  over 
the  interspaces. 

The  sesamoid  bones  of  the  thumb  lie  just  beyond  the  metacarpo-phalangeal 
joint, — that  is,  to  its  distal  side, — so  that  in  amputation  through  the  joint  the 
incision  into  the  articulation  should  be  made  on  the  proximal  side  of  these  bones. 

The  knuckles,  consisting  of  three  rows,  are  formed  by  the  distal  ends  of  the 
proximal  bones.  Thus,  the  heads  of  the  metacarpals  form  the  first,  the  distal  ends 
of  the  first  phalanges  the  second,  and  the  distal  ends  of  the  second  phalanges  the 


38  SURGICAL   A  \ATOMY. 

third,  row.     To  enter  the  knuckle-joint  for  amputation  the  knife  should  be  carried 
a  little  in  advance  of  the  prominence  of  the  knuckle. 


NERVE  STKKTCIIIXC  AND  NKRVK  SICCTIOX  have  now  become  so  well-recog- 
ni/ed  and  common  procedures  that  the  following  tew  instructions  may  he  an 
aid  to  the  student,  both  in  retaining  his  knowledge  of  the  anatomic  relations 
and  in  subsequent  practical  surgical  utility: 

The  inlii-i  (i.i-;!liit'</  or  l>r<irli'ml  plexus  can  be  stretched  in  the  axilla  through  an 
incision  made  in  the  line  of  the  axillary  artery.  Each  branch  or  cord  must  lie 
identified,  raised  upon  a  blunt  hook  or  anenrysm  needle,  and  pulled  with  moderate 
tension  in  proportion  to  the  size  of  the  nerve  being  manipulated.  The  mnllim 
ncrrc  is  found  upon  the  outer  side  of  the  brachial  artery  in  its  upper  third,  anterior 
to  the  artery  in  its  middle  third,  and  on  its  inner  side  in  its  lower  third.  It  can 
be  reached  in  the  lower  end  of  the  forearm  through  an  incision  parallel  with  the 
ulnar  border  of  the  flexor  carpi  radialis  tendon,  where  it  will  be  found  between  this 
tendon  and  the  outermost  tendon  of  the  flexor  sublimis  digitorum.  The  i.Hi  i-iml 
i-ntfineous  or  musculo-eutaneous  ncrr/-,  before  it  pierces  the  eoraco-brachialis  muscle. 
lies  upon  the  outer  side  of  the  median  nerve,  and  lower  down,  between  the  biceps 
and  brachialis  anticns  muscles.  Upon  the  outer  side  of  the  tendon  of  the  biceps 
it  becomes  an  occupant  of  the  superficial  fascia. 

The  Infi'i'iuil  ciiliiin-niifi  ni'iTi'  is  found  upon  the  inner  side  of  the  brachial 
artery  in  the  upper  third  of  the  arm,  and  upon  the  inner  side  of  this  vessel  and 
the  median  nerve  in  the  middle  of  the  arm. 

The  iifimr  nerve,  in  the  upper  two-thirds  of  the  arm,  is  on  the  inner  side  of 
the  internal  cutaneous,  and  is  readily  differentiated  from  it  because  of  its  larger 
size.  It  is  easily  found  behind  the  internal  condyle,  one  of  the  best  locations  for 
securing  it  with  little  effort  and  slight  danger  of  confounding  it  with  other  struc- 
tures. It  is  also  readily  found  in  the  lower  part  of  the  forearm,  under  the  flexor 
carpi  ulnaris  tendon  on  the  inner  side  of  the  ulnar  artery. 

The  musculo-spiral  ncm<  is  found  deeply  situated  upon  the  outer  side  of  the 
lower  end  of  the  arm,  between  the  brachialis  anticus  and  the  supinator  longus ;  in 
the  tnrttniliital  fossa,  opposite  the  tendon  of  the  biceps  and  the  bifurcation  of  the 
brachial  artery,  it  divides  into  the  radial  and  posterior  interosseous,  where  both 
nerves  may  be  stretched. 

The  radial  nerve  is  also  readily  found  at  the  middle  of  the  front  of  the  fore- 


PLATE 


ANTERIOR  VIEW  OF  UPPER  EXTREMITY- MOTOR  POINTS. 
40 


PLATE  IX. 


MOTOR  POINTS  AND  LINES  OF  INCISIONS  FOR  POSTERIOR  CIRCUMFLEX  ARTERY  AND  MUSCULO-SPIRAL  NERVE, 

41 


PLATE  X. 


Acromion  process 
Coracoid  process 
Acromial  angle 


Spine- 


DORSUM  OF  SCAPULA  SHOWING  ACROMIAL  ANCLE. 
43 


PLATE  XL 


LINES  OF  INCISIONS  FOR  DISSECTION  AND  LINE  FOR  AXILLARY  ARTERY, 

45 


-;   ANATOMY   or   THE    ITl'ER    EXTREMITY. 


ami  under  the  ulnar  margin  of  the  supinator  longus  muscle  on  the  outer  side  of 
the  radial  artery. 

The  motor  points  are  places  where  the  nerves  heroine  superficial  by  perfor- 
ating the  deep  fascia,  or  \vliere  they  emerge  through  or  between  muscles  to  take  a 
superficial  course.  It  is  at  these  points  that  response  is  most  readily  secured  <o  a 
concentrated  electric  current  from  a  small  electrode,  causing  marked  tingling  and 
decided  muscular  contraction  with  a  strength  ot  current  that  is  hardly,  or  not  at 
all,  noticeable  at  other  parts  of  the  cutaneous  surface.  The  points  are  well  shown 
in  the  annexed  figures. 

Measurements  of  the  arm  are  made  from  the  tip  of  the  acromion,  or  the 
angle  of  junction  of  the  acromion  with  the  spine  of  the  scapula,  to  the  external 
cuiidyle,  and  with  the  forearm  extended  and  supinated  from  this  to  the  tip  of  the 
styloid  process  of  the  radius.  Each  point  should  be  identified  and  marked  with  a 
dot  of  ink,  for  the  custom  of  identifying  these  points  while  measuring  with  a  tape, 
may  cause  errors  of  one-quarter  or  one-half  of  an  inch  in  two  successive  measure- 
ments by  the  same  individual.  This  is  particularly  important  in  medico-legal 
gases. 

DISSECTION.  —  The  dissection  of  the  upper  extremity  includes  as  much  of  the 
front  and  back  of  the  chest  as  is  connected  with  the  arm,  together  with  the 
shoulder,  axilla,  arm,  forearm,  and  hand.  Preparatory  to  making  the  dissection, 
the  cadaver  should  be  placed  upon  its  back,  with  the  arm  at  a  right  angle  to  the 
body,  and  resting  upon  a  flat  board,  to  which  the  hand  should  be  fastened  in 
supination.  A  block  four  to  six  inches  in  thickness  should  be  placed  under  the 
shoulders.  For  purposes  of  preservation  the  part  should  be  bandaged  as  high  as 
the  middle  of  the  arm,  preferably  with  some  oiled  paper,  oiled  muslin,  or  rubber, 
to  prevent  drying.  This  covering  should  be  removed  as  the  dissection  progre>M»- 
and  reapplied  when  discontinuing. 

In  reflecting  the  skin  it  is  advisable  to  make  as  large  flaps  as  possible.  My 
reason  is  a  two-fold  one  :  first,  there  is  no  better  covering  than  the  skin  to 
preserve  the  moisture  of  the  underlying  structures  ;  and,  second,  the  dissector  is 
thus  enabled  to  review  the  surface  anatomy  of  the  part,  from  time  to  time,  and 
study  carefully  the  relations  of  the  surface  markings  to  the  deeper  structures. 
In  removing  the  skin  from  the  front  of  the  chest  no  more  than  three  incisions  are, 
therefore,  advisable:  one  extending  along  the  middle  of  the  entire  length  of  the 
sternum,  another  from  the  upper  end  of  this  incision  along  the  clavicle  to  its 
acromial  end,  and  thence  downward  over  the  shoulder  to  the  outer  side  of 
the  middle  of  the  arm,  and  a  third  from  the  lower  end  of  the  sternal  incision 
transversely  outward  to  the  line  of  the  posterior  fold  of  the  axilla. 


-4S  sritdirAL   AXATOMY. 


Now  grasp  only  tlie  skin  at  the  superior  sternal  angle  with  a  pair  of  forceps 
and  gradually  relied  it  by  severing  it.-  e(innecti(iii  to  the  underlying  fascia  with  a 
knife;  but  as  soon  as  enough  has  lieeii  turned  hack  to  he  readily  grasped  by  the 
lingers,  they  should  take  the  place  of  the  forceps,  because  the  work  thus  becomes 
easier  and  is  more  rapidly  and  more  neatly  executed.  The  superficial  fascia  and 
its  nerves  and  vessels  thus  become  exposed,  though  in  the  infra-clavicular  and 
shoulder  regions  there  will  he  seen  a  thin  layer  of  muscular  libers  passing  over  the 
clavicle  into  the  neck.  This  is  the  origin,  or  inferior  attachment,  of  the  platysma 
myoides  muscle,  a  superficial  structure  by  which  the  skin  of  the  neck  is  moved.  It 
is  a  remnant  of  a  well-marked  and  useful  structure  —  the  pannim/nx  rarnoxnx  — 
a  thin  layer  of  muscular  libers  existing  in  the  lower  animals;  it  is  situated  in  the 
superficial  fascia,  and  enables  its  possessor  to  shake  off  flies  and  other  insects  by 
rapid  vibratory  motions  of  the  hide.  It  is  the  underlying  red  muscular  structure 
which  one  sees  in  fancy  figures  cut  in  (|iiarters  of  beef  and  mutton.  A  slash  of 
the  knife  immediately  after  skinning  causes  a  wide  separation  of  the  severed  ends 
of  the  still  warm  muscular  fibers,  which  contract  as  soon  as  cut. 

The  skin  over  the  sternum  is  rather  thicker  than  over  the  lateral  regions  of 
the  thorax,  can  not  readily  be  raised  up  in  folds,  and  retracts  considerably 
when  divided.  In  males  it  is  often  covered  with  a  growth  of  hair.  Keloid 
growths  arc  not  uncommonly  seen  here. 

The  superficial  fascia  consists  of  both  a  superficial  layer  of  connective  tissue. 
quite  rich  in  adipose  substance,  occupying  its  meshes,  and  a  <!<']>  layer,  which  is 
membranous  and  resembles  the  deep  fascia  to  which  it  is  attached.  Met  ween  the 
two  layers  are  found  the  mammary  gland,  the  vessels,  and  the  nerves.  Over  the 
sternum  the  adipose  tissue  is  less  abundant  than  elsewhere  in  the  anterior  thoracic 
region;  and  in  corpulent  persons,  therefore,  the  sternal  area  is  relatively  depressed. 
The  fascia  is  firmly  adherent  to  the  periosteum  of  the  sternum. 

The  vessels  of  the  superficial  fascia  are  as  follows:  Five  or  six  jierforatin;/ 
branches  of  the  intermit  nunnniai-i/  a  i-fe  i-  1/.  which  appear  near  the  sternum  and  are 
directed  outward,  the  upper  three  usually  going  to  the  mammary  gland  and 
becoming  enlarged  in  women  during  lactation,  the  lower  two  or  three'  supplying 
the  pectoralis  major.  The  upper  five  or  six  imtn-im-  mtffrcostal  branches  of  the 
internal  mam  tnary  also  appear  upon  the  front  of  the  chest  to  supply  the  pectoral 
muscles  and  the  mammary  gland.  Thoraeie  liraneliex  nf  fin1  acromio-thoracic  artery  — 
two  or  three  small  vessels  —  descend  upon  the  chest  at  the  middle  of  the  clavicle 
to  supply  the  pectoralis  major  and  anastomose  with  the  preceding.  The  aei'mnial 
branches  of  the  same  go  to  the  shoulder  and  supply  the  deltoid  ;  they  anastomose 
upon  the  top  of  the  shoulder  with  the  supra-scapular  and  posterior  circumflex 
arteries.  The  descending  branches  pass  down  the  delto-pectoral  sulcus  beside  the 


PLATE  XII, 


Branch  of  transversalis  colli  a. 
Branch  of  acromlo-thoracic  a 


Branch  of  lonp  thoracic  a.- 


Mammary  gland  in  superficial  fascia 


Perforating  branches  of  internal  mammary  a.- 


SUPERFICIAL  FASCIA  OF  PECTORAL  REGION. 
49 


PLATE  XII. 


Serratus 
magnus  m. 


lateral  Cutaneous 


Latissimus  dorsi  m.- 


External  oblique  m.— 


Internal  oblique  m. 
in  triangle  of  Petit 


v 


ectoralis  major  m. 


Lineae 
Transversae 


Linea  Semilunaris 


Anterior  cutaneous 
nerves 


ANTERIOR  CUTANEOUS  AND  LATERAL  CUTANEOUS  NERVES. 
62 


SURFACE   ANATOMY   OF   Till-:   I'l'I'KR    KXTIIKMITY.  '>'•'> 


cephalic  vein.  Tin-  /-/////  tlim-m-ir  iniii-i/  scn«ls  branches  to  tlie  mammary  gland 
and  (lie  superficial  fascia.  All  of  these  vessels  supply  the  fascia  and  skin  of 
this  region,  and  are  accompanied  by  veins  and  lymphatics,  which  latter  become 
visible  during  inflammatory  diseases. 

The  nerves  in  the  fascia  of  this  region  are  branches  of  the  cervical  plexus 
and  the  intcrcostals.  The  cervical  plexus  sends  down  inner  or  Kiij>rii-sti  nut/  l>r<ni<-li<'x, 
which  pass  over  the  sternal  end  of  the  clavicle  to  the  upper  part  of  the  sternal 
region  of  the  chest,  mii/il/i'  or  xiijir<i-r/nr/rii/iif  In'n  ui'licx,  to  the  infra-clavicular 
region  ;  and  external  or  xiijiru-urroiniiil  hruitrlifx,  to  the  upper  and  hack  part  of  the 
shoulder.  These  three  sets  comprise  the  descending  branches  of  this  plexus. 
The  mill  I'i'ir  cutaneous  /inim-l/ix  of  the  upper  six  intercostal  nerves  pierce  the 
pectoralis  major  to  supply  the  skin  and  fascia  over  this  muscle  and  the  region  of 
the  sternum.  A  few  twigs  from  the  third  and  fourth  go  to  the  mammary  gland. 
The  lateral  cutaneous  nerves,  branches  of  the  intercostal*,  pierce  the  external  inter- 
costal muscles  and  emerge  between  the  digital  ions  of  the  serratus  magnus  muscle. 
They  divide  into  anterior  and  posterior  branches,  the  former  turning  upward  over 
the  lower  border  of  the  pectoralis  major  to  the  fascia  and  skin  of  the  chest  and 
to  the  mammary  gland,  and  the  posterior  passing  backward  to  the  dorsum  of  the 
trunk  over  the  anterior  margin  of  the  latissimns  dorsi. 

The  lymphatic  vessels  of  the  anterior  chest  region  converge  toward  the 
axillary  glands,  are  quite  sparse,  and  in  their  normal  condition  are  as  difficult  to 
distinguish  here  as  elsewhere. 

The  mammary  glands  —  smooth,  rounded  prominences  —  form  the  bust  or 
breasts  of  women.  They  are  rudimentary  in  the  male,  although  exceptional 
instances  have  been  reported  of  men  nursing  children  from  their  breasts.  They 
are  more  or  less  hemispheroid,  with  the  flat  or.  concave  base  resting  upon  the 
deeper  layer  of  the  superficial  fascia.  They  extend  from  the  third  to  the  seventh 
rib  and  from  the  edge  of  the  sternum  to  the  anterior  axillary  border.  Their 
longest  diameter  extends  upward  and  outward  toward  the  axilla.  The  outline  of 
the  base  of  the  gland  is  not  circular,  but  rather  triangular,  inasmuch  as  there  are 
two  extensions  —  an  upper  and  a  lower  —  of  variable  size,  one  toward  the  axilla, 
the  other  toward  the  sternum.  The  upper  of  these  axillary  extensions  may  even 
curve  around  the  lower  border  of  the  great  pectoral  muscle  ;  furthermore,  a  com- 
pletely detached  portion  of  the  gland  or  a  supernumerary  gland  may  lie  in  the 
axilla  and  be  the  starting-point  of  a  tumor. 

Small  portions  of  the  gland  may  lie  beneath  the  deep  fascia,  in  or  upon  the 
pectoralis  major,  and  the  suspensory  ligaments  may,  according  to  Stiles,  contain 
glandular  processes.  All  of  these  facts  are  of  importance  in  the  diagnosis  and 
treatment  of  mammary  carcinoma.  In  the  female  they  vary  in  size  during  life, 


.".I  SURGICAL    AXATOMY. 

being  rudimentary  in  childhood,  developing  at  puherty,  and  becoming  more 
enlarged  during  pregnancy,  to  reach  their  highest  development  ni'ter  childbirth 
and  during  lactation.  They  diminish  after  lactation,  and  thus  alternately  become 
larger  and  smaller  during  successive  births,  until  the  child-hearing  and  suckling 
periods  have  been  passed,  when  they  atrophy  and  again  assume  a  rudimentary  state. 

The  mamma  is  composed  of  tissue  of  a  glandular,  fibrous,  and  fatty  type. 
The  glandular  structure  is  racemose,  and  consists  of  small,  secreting  lobules,  with 
confluent  duets,  the  lobules  uniting  to  form  lobes,  each  of  which  has  a  single  main 
duct  terminating  in  the  nipple.  There  are  from  fifteen  to  twenty  of  these  lac- 
tiferous or  galactophorous  duets.  They  converge  toward  the  nipple  and  form  under 
the  areola  ampulla-  or  dilatations,  which  serve  as  reservoirs  for  the  milk;  they 
again  contract  as  they  enter  the  nipple  and  open  upon  the  summit  by  orifices 
smaller  than  the  ducts  themselves.  The  ducts  are  composed  of  connective  tissue 
and  longitudinal  muscular  fillers,  and  are  lined  with  tessellated  epithelium,  con- 
tinuous with  the  skin  externally  and  with  the  glandular  epithelium  internally. 
The  fibrous  structure  consists  of  the  perimammary  investiture  of  superficial  fascia 
(capsule  of  the  gland)  and  its  intramammary  extensions,  which  form  supporting 
and  connecting  septa  between  the  lobes  of  the  gland.  Some  processes  of  the  fascia 
go  to  the  nipple  and  skin  and  are  called  suspensory  ligaments  (ligaments  of  Sir 
Astley  Cooper).  The  fatty  tissue  covers  the  surface  of  the  gland  and  its  component 
lobes  and  consists  of  two  portions,  the  perimammary  and  interlobar  ;  it  does  not, 
however,  exist  within  or  immediately  beneath  the  nipple.  The  amount  of  the  fatty 
tissue,  rather  than  that  of  the  glandular  structure,  determines  the  si/.e  of  the  breast. 
The  deep  surface  of  the  capsule  of  the  gland  is  connected  to  the  deep  or  pectoral 
fascia  by  loose  connective  tissue,  in  which  a  bnrsa  sometimes  exists.  At  times  this 
connective  tissue  is  so  loose  in  female  savages,  as  in  the  Hottentots,  that  the  glands 
can  be  thrown  over  the  shoulder,  and  a  child  suckled  while  being  carried  upon  the 
back.  Surmounting  the  mammary  gland  is  a  conic  elevation,  the  nipple. 

The  nipple,  or  mamilla,  is  found  over  the  fourth  intercostal  space,  and  is  a 
dark-colored,  flattened,  cylindric  elevation,  composed  of  erectile  tissue,  and  very 
sensitive-.  It  is  on  the  left  side  and,  more  especially  in  the  male,  is  a  guide  to  the 
location  of  the  apex  beat  of  the  heart,  which  is  found  one  and  one-half  inches 
below  and  three-fourths  of  an  inch  to  its  inner  side.  It  has  a  puckered,  wrinkled 
skin,  some  papilla1,  and  upon  its  summit  are  the  openings  of  the  lactiferous  ducts. 
It  is  composed  of  vessels  mixed  with  smooth  muscular  fibers,  and  is  erectile.  It  is 
surrounded  by  a  pigmented  areola,  of  a  delicate  rose  color  in  virgins,  which  becomes 
darker  during  pregnancy,  subsequently  fading  somewhat,  but  not  enough  to  regain 
its  original  appearance.  In  the  areola  near  the  base  of  the  nipple  are  numerous 
sebaceous  glands, — the  tubercles  of  Montgomery, — which  enlarge  during  pregnancy 


PLATE  XIV. 


Lactiferous  duct 


Acinae  of  gland 


Ampulla 


Nipple 


Adipose  tissue 


Areola  and  tubercles  of  montgomery 


MAMMARY  GLAND 
55 


tt'RFACE  A.\.\TOMy   OF   Till-:   r/'/'A'A'    KXTHKMITY.  .',7 

and  lactation  ,'111(1  liave  the  appearance  of  subcutaneous  tubercles.  They  secrete  a 
greasy  substance  t<>  protect  the  nipple  during  suckling.  These  glands  may  be 
primarily  all'ected  by  carcinoma  or  sarcoma,  which  may  secondarily  involve  the 
mammary  gland. 

The  skin   of  the  nipple   is  thin  and  very  sensitive,  and    i-  ot'ien    the  seat  of 
])aint'ul  and  intractable  lissures  during  nursing.     Chronic  inflammation  of  the  skin 
of  the  nipple  (ec/eina)  is  at  times  the  accompaniment  of  beginning  Paget's  disi 
mammary  epithelioma,  and  cancer  of  the  lnvaM. 

BI.OOD  AND  XKKVK  Srn-i.Y. — The  niammary  gland  is  nourished  by  the  long 
thoracic.-  branch  of  the  uj-illm-ii  artery,  the  unl/rior  intercostal,  and,  especially,  the 
/irii'iii'iiti/ii/,  branches  of  the  internal  mammary  artery,  and  the  hif<  irnxldl.  artc'ries. 
The  veins  accompany  the  arteries  and  also  form  an  anastomotic  circle  about  the 
nipple  (circulus  venosus,  Haller),  from  which  large  branches  carry  its  contents  to  the 
circumference  of  the  gland,  whence  it  is  taken  to  the  axillary  and  internal  mam- 
mary veins. 

The  lymphatic  channels  play  a  conspicuous  role  in  inflammatory  and  neo- 
plastic  processes.  Most  of  the  mammary  lymphatics  go  to  the  axillary  glands, 
though  a  few  enter  the  anterior  mcdiastinal  lymphatics,  following  the  mammary 
branches  of  the  internal  mammary  artery.  When  the  breasts  are  unusually  large, 
the  lymphatics  communicate  across  the  sternum  ;  this  is  one  of  the  anatomic' 
explanations  of  the  occurrence  of  cancer  in  both  breasts.  In  advanced  cases  of 
carcinoma  of  the  breast  the  glands  in  the  infra-  and  supra-clavicular  fossae  often 
become  involved,  in  addition  to  the  axillary  glands.  The  lymph  from  the  mam- 
mary gland  first  passes  into  the  glands  along  the  anterior  fold  of  the  axilla  and 
then  into  those  along  the  axillary  vessels.  As  metastasis  from  cancers  follows  the 
course  of  the  lymphatics,  the  glands  along  the  anterior  fold  are  first  involved  and  ' 
then  those  along  the  axillary  vessels  are  affected.  In  its  course  the  lymph  will, 
after  a  time,  involve  the  glands  along  the  subclavian  vessels.  The  anastomosis 
between  the  submammary  lymphatics  and  the  intramammary  lymphatics  is  so 
free  that  the  operation  for  carcinoma  of  the  breast  which  promises  the  best  results 
is  that  which  removes  the  entire  gland,  the  skin  wide  of  the  diseased  area,  totally 
excises  the  submammary  and  paramammary  connective  tissue,  the  pectoral  fascia, 
sternal  portion  of  the  pectoralis  major,  the  pectoralis  minor,  the  lymphatics  and 
connective  tissue  of  the  armpit,  deep  infraclavicular  and  subclavian  triangles. 
The  lymphatics  of  the  axilla,  deep  infraclavicular  triangle,  and  subclavian  tri- 
angle are  not  necessarily  involved  through  the  superficial  lymphatic  channels, 
but  may  be  directly  infected  through  the  submammary  lymphatic  vessels.  If 
the  axillary  vein  be  wounded  in  the  operation  for  removal  of  the  breast,  a  small 
opening  may  be  closed  by  pinching  up  the  torn  place  and  applying  a  lateral 


r,S  SriiCK'AI.    AX  ATOMY. 

ligature;  but  if  the  wound  be  large,  tbe  vein  must  be  tied  to  either  side  of  the  rent. 
When  the  axillary  vein  is  included  in  malignant  tissue,  ligatures  should  be  applied 
above  and  below  and  the  involved  portion  of  the  vein  excised. 

The  nerve  supply  is  from  the  n/tlrr/nr  cutaneous  /'i-i/nr/nx  of  the  third,  tburili. 
and  fifth  intercostal,  the  ilrxccitil'nuj  branches  of  the  cervical  plexus,  and  the  lateral 
cutaneous  branches  of  the  third,  fourth,  and  fifth  inteivostals.  This  arrangement 
of  the  nerves  explains  the  pains  tell  in  the  shoulder,  neck,  back,  and  down  the 
arm  in  painful  breast  affections,  such  as  cancer,  mastitis,  and  ab<c< 

The  largest  artery  divided  in  excision  of  the  breast  is  the  Imii/  //inrm-ir,  also 
called  <!cr]>  external  mammary  in  contradistinction  to  the  .•niju-rjicinl  external  mam- 
mary, which  is  not  constant.  The  superficial  external  mammary  is  a  branch 
either  of  the  third  division  of  the  axillary  or  of  the  first  portion  of  the  brachial, 
and  reaches  the  gland  by  passing  through  the  superficial  fascia  of  the  axilla. 

Because  of  the  close  relation  which  this  gland  bears  to  the  pectoralis  major 
muscle,  all  movements  of  the  arm  affect  the  gland,  more  or  less.  This  is  not 
particularly  noticeable,  ordinarily,  but  it  becomes  unpleasantly  evident  in  painful 
affections  of  the  breast,  as  in  mammary  abscess. 

Mammary  abscess  may  be  confined  between  the  septa  of  the  gland,  may  be 
diffused  throughoul  the  organ,  or  may  occur  in  ihe  submammary  connective  tissue  ; 
in  this  last  event  it  will  most  likely  point  at  the  anterior  fold  of  the  axilla.  Inci- 
sions into  the  breast  should  be  made  toward  the  nipple,  so  as  not  to  sever  the 
lactiferous  ducts  whicli  converge  toward  this  point.  After  opening  an  abscess  of 
the  mammary  gland,  the  fibrous  septa  of  the  abscess  should  be  broken  down  in 
order  that  perfect  drainage  may  be  obtained.  After  all  operations  upon  the 
mammary  gland,  and  in  the  treatment  of  inflammatory  affections  of  the  gland,  the 
whole  upper  extremity  should  be  bandaged  to  the  chest  as  in  fractured  clavicle,  so 
that  movements  of  the  arm  and  pectoralis  major  will  not  prevent  rest  of  the  part. 
Enlargement  of  the  bursa  under  the  breast  would  constitute  a  submammary  cyst. 
In  long-standing  scirrhus  (hard  cancer)  of  this  gland  the  nipple  is  retracted  and 
the  skin  dimpled,  because  of  traction  by  the  fibrous  septa  and  lactiferous  ducts. 

In  detecting  adhesions  between  the  mammary  gland  and  the  pectoralis  major,  as 
in  carcinoma  of  the  breast,  the  gland  should  be  moved  in  the  direction  of  the  libers 
of  that  muscle  ;  for  if  the  gland  is  moved  in  a  direction  which  is  across  that  of  the 
fibers  of  the  muscle,  the  pectoralis  major  will  move  with  the  gland. 

A  suspected  tumor  in  the  mammary  gland  is  most  readily  detected  by  placing 
the  palm  of  the  hand  flat  upon  the  organ  and  compressing  the  latter  against 
the  thorax.  If  the  enlargement  be  inflammatory,  the  hand  feels  nothing  but 
the  lumpy  and  wormy  sensation  of  the  swollen  ducts  and  acini.  This  is 
Spence's  test. 


PLATE  XV, 


.ial  fascia 

-h  of  lateral  cutaneous  n. 
Intercosto-humeral  n. 


ephalic  v. 


Deep  fascia 


Axillary  fascia 


DEEP  FASCIA  OR.  PECTORAL  FASCIA  AND  AXILLARY  FASCIA. 
59 


PLATE  XVI, 


Clavicle. 

Costo-cnracD/d  mem,- 
Pec  fora /is  major 


Teres  major. 


•faffss/mus 

-dors/, 


--•Subscapularis. 
es  major. 

-Latissimus  dorsl. 


fliagrsm  shnwing  line  of  section. 


DIAGRAM  OF  PECTORAL  FASCIA  AND  AXILLARY  FASCIA. 
62 


Xl'ltl-'ACK   ANATOMY   OF  THE   UTTER   EXTREMITY.  (>'•"> 

Congenital  variations  and  anomalies  of  the  breast. — The  nij)])k>  may  lail 
to  develop  properly,  and  thus  appear,  in  the  adult,  to  be  retracted.  Absence  of  the 
nipple  (uilii'liit)  is  sometimes  observed.  When  supernumerary  nipples  occur,  the 
condition  is  spoken  of  as  po!i/tli<///i.  Supernumerary  mammas  are  found  at  times 
in  the  axilla,  anterior  thoracic  wall,  or  even  in  the  groin,  on  the  back  or  thigh. 
The  condition  is  known  a,s polymastia  or  polymaxia. 

Congenital  absence  of  one  or  both  breasts  (mn/r-ln)  is  much  more  rarely 
encountered.  The  breasts  may  fail  to  develop  properly,  remaining  rudimentary 
and  small.  Such  condition  is  termed  ii/icrtniiti-iii. 

When  the  mamma'  are  unusually  large  in  males,  the  condition  is  called 
gynecomastia.  Not  a  few  of  these  anomalies  of  the  breast  are  associated  with 
imperfections  or  malformations  of  the  genitalia. 

In  infants,  shortly  after  birth,  the  breasts  sometimes  become  increased  in  size 
and  secrete  a  turbid  fluid.  Occasionally  it  happens  that  in  girls  at  the  age  of 
puberty  the  mainline  develop  unequally,  one  becoming  rather  rapidly  increased  in 
size,  while  the  other  remains  for  a  time  retarded  in  growth.  The  gland  may 
become  slightly  larger  and  somewhat  painful  in  boys  at  the  age  of  puberty. 

DISSECTION. — The  deep  fascia  is  exposed  by  removal  of  the  superficial  fascia, 
which  should  be  dissected  off  in  the  same  manner  as  was  the  skin. 

The  deep  fascia  or  pectoral  fascia  is  continuous  with  that  of  the  neck, 
shoulder,  arm,  back,  and  abdomen.  Tt  consists  of  two  layers,  the  superficial  and  the 
deep.  The  superficial  layer  is  attached  to  the  anterior  surface  of  the  clavicle  and 
sternum,  and  blends  below  with  the  deep  fascia  of  the  external  oblique  muscle. 
It  forms  the  sheath  of  the  pectoralis  major  muscle.  The  deep  layer  lies  beneath 
the  pectoralis  major,  and  can  not  be  studied  until  that  muscle  has  been  removed. 

DISSECTION. — The  superficial  layer  of  the  dee])  fascia  should  now  be  reflected, 
and  in  effecting  its  removal  the  scalpel  should  cut  at  right  angles  to  the  line  of  the 
muscle  fibers.  Its  connection  with  the  deep  layer  along  the  lower  border  of  the 
pectoralis  major  should  not  be  severed  until  the  axillary  fascia  and  the  manner  of 
its  formation  has  been  demonstrated,  as  this  is  the  point  where  the  two  layers  blend 
to  form  that  fascia. 

The  pectoralis  major  muscle  is  large,  thick,  flat,  and  triangular,  and  covers 
the  front  of  the  chest  and  axilla.  Its  base  rests  upon  the  sternum  and  inner  half 
of  the  clavicle,  and  its  apex  is  between  the  biceps  and  deltoid  muscles  in  the  upper 
part  of  the  arm.  It  is  divided  by  a  slight  separation  of  its  fibers  into  an  upper,  or 
clavicular,  and  a  lower,  or  chondro-sternal,  portion.  The  clavicular  portion  arises 
from  the  anterior  surface  of  the  sternal  half  of  the  clavicle  and  from  the  adjacent 
portion  of  the  sterno-clavicular  articulation  ;  its  outermost  fibers  are  in  contact 
with  the  anterior  margin  of  the  deltoid.  The  chondro-sternal  portion  arises  from 


c,l  SURGICAL   ANATOMY. 

the  lateral  half  of  the  entire  length  of  the  sternum,  except  below  the  attachment 
of  the  seventh  costal  cartilage:  from  the  cartilages  of  the  true  ribs,  excepting  fre- 
quently eillier  the  lirst  or  the  seventh,  or  both  :  from  the  sternal  end  of  the  sixth 
rib;  and  from  tin-  a|>oneurosis  <if  the  adjacent  portion  of  the  external  oblique. 
From  this  extensive  origin  the  libers  converge  upon  the  front  of  the  arm,  forming 
a  flat  tendon  about  two  inches  in  length,  which  is  inserted  into  the  anterior  hicipi- 
tal  ridge  of  the  hnmerns.  The  lowermost  libers  of  origin  of  this  portion  have  the 
highest  insertion  on  the  ridge,  and  the  uppermost  libers  have  the  lowest.  Thus, 
the  most  inferior  fibers  are  overlapped  near  their  insertion  by  the  middle  libers, 
and  these  iii  turn  by  the  upper.  The  clavicular  fibers  pass  downward  and  out- 
ward, the  central  fibers  horizontally  outward,  and  the  lower  libers  upward  and 
outward.  The  anterior  layer  of  the  doubled  tendon  of  insertion  is  thicker  than 
the  posterior,  and  receives  the  fillers  of  the  clavicular  and  upper  chondro-sternal 
portions,  the  posterior  portion  receiving  the  remaining  fibers  from  the  lower  half 
of  the  muscle.  The  tendon  of  insertion  is  connected  with  that  of  the  deltoid.  It 
sends  a  prolongation  upward  over  the  bicipital  groove  to  the  greater  tnberosity, 
thus  binding  down  the  long  head  of  the  biceps,  another  backward  to  line  the 
groove,  and  still  another  to  the  deep  fascia  of  the  arm. 

The  choiNlro-sternal  portion  lies  upon  the  sternum,  ribs,  and  costal  cartilages, 
the  intercostal  muscles,  the  peetoralis  minor,  part  of  the  serratus  magnus,  and  the 
deeji  layer  of  the  deep  fascia,;  the  clavicular  portion  lies  in  front  of  the  costo- 
coracoid  membrane  and  the  structures  piercing  this  membrane.  The  peetoralis 
major,  peetoralis  minor,  and  deep  layer  of  the  deep  fascia  form  the  anterior 
axillary  wall.  Between  the  clavicular  portion  of  the  peetoralis  major  and  the  ante- 
rior edge  of  the  deltoid  is  the  delto-pectoral  sulcus,  or  cephalic  groove,  which 
accommodates  the  cephalic  vein  and  the  descending  or  humeral  branch  of  the 
acromio-thoraeic  artery.  Internally,  in  some  muscular  individuals  the  fibers  of 
the  peetoralis  major  decussate  with  those  of  its  fellow  of  the  opposite  side. 
Occasionally,  muscular  fibers  are  found  along  the  sternum,  from  the  manubrium 
above  to  the  sheath  of  the  rectus  below,  and  form  the  i-<rtus  xfn-iinlix  muscle.  The 
lower  edge  of  the  peetoralis  major  forms  the  anterior  axillary  margin  and,  with 
the  latissimus  dorsi,  converges  toward  the  outer  part  of  the  space. 

The  cellular  interval  between  the  chondro-sternal  and  clavicular  portions  of 
the  muscle  is  represented  by  a  depression  on  the  chest  when  the  arm  is  strongly 
abducted,  and  with  the  arm  at  a  right  angle  to  the  body  corresponds  to  a  line 
drawn  from  the  sterno-elavicular  joint  to  the  middle  of  the  bend  of  the  elbow. 
An  incision  through  this  interval  exposes  the  first  portion  of  the  axillary  artery. 

The  ACTIONS  of  the  peetoralis  major  are  complex,  though  its  general  function 
is  to  draw  the  elbow  across  the  chest  in  anterior  adduction.  It  is  also  an  inward 


PLATE  XVII. 


Trapezius  m 


Posterior  belly  of  omo-hyoid  m.- 
Sterno-mastoid  m. 


Anterior  belly  of  omo-hyoid  m 
Sterno-hyoid  m.- 


Sterno- thyroid  m. 

Chondro-sternal  head  of  pectoralis  major  m. 
Clavicular  head  of  pectoralis  major  m. 
Latissimus  dorsi  m. 
Deltoid  m: 


Serratus  magnus  m 
Teres  major  m. 


Latissimus  dorsi  rr 
Triceps  m. 


External  oblique 


Pectoralis  major  m.  (cut)- 
Short  head  of  biceps  m. 
Long  head  of  biceps  m.- 


PECTORALIS  MAJOR  MUSCLE  AND  PECTORALIS  MINOR  MUSCLE. 

65 


SURFACE  ANATOMY  OF  THE  CPPKU   EXTHKMITY.  67 

rotator  of  the  humerus.  The  clavicular  portion  aids  the  anterior  libers  of  the  del- 
toid in  elevating  the  arm  and  drawing  it  forward,  while  the  lowermost  fibers  of  the 
ehondro-sternal  portion  draw  the  arm  downward  and  forward.  The  pectoralis  major 
is  a  hugging  muscle.  If  the  arm  be  fixed,  its  action  is  reversed.  It  then  would 
help  to  elevate  the  body  suspended  by  the  arms,  would  elevate  the  body  in  dipping 
between  parallel  bars,  and  would  be  a  powerful  aid  in  difficult  respiration  when 
the  arms  are  fixed.  It  reaches  a  remarkable  development  in  winged  animals,  in 
which  its  size  may  be  inferred  from  the  thickness  of  their  breasts.  The  pectoralis 
major  is  often  the  seat  of  earcinomatous  deposits  in  cases  of  malignant  disease  of 
the  breast;  and,  in  such  cases,  the  surgeon  does  not  hesitate  to  remove  a  part  or 
1 1 ic  whole  of  the  muscle.  In  the  most  radical  operation  for  mammary  cancer  the 
ehondro-sternal  portion  of  the  muscle  is  always  removed.  After  this  operation 
hypertrophy  of  the  clavicular  portion  of  the  pectoralis  major  and  the  anterior  part 
of  the  deltoid  compensates  for  the  loss  of  the  ehondro-sternal  portion  of  the  pec- 
toralis major. 

Nourishment  is  supplied  to  this  muscle  by  brandies  of  the  axillary  and  inter- 
nal mammary  arteries,  especially  the  acromio-thoracic  and  long  thoracic  branches 
of  the  axillary  which  ramify  in  the  anterior  pectoral  region. 

Its  nerves  arc  the  external  and  internal  anterior  thoracic. 

DISSECTION. — The  next  step  in  the  dissection  is  to  detach  the  clavicular  por- 
tion of  tlie  pectoralis  major  from  the  clavicle  and  displace  it  downward  and  out- 
ward, when  will  be  seen  a  triangular-shaped  space,  the  floor  of  which  is  formed  by 
the  deej)  pectoral  or  clavi-pectoral  fascia.  This  triangular-shaped  space  is  the 
superficial  infra-clavicular  triangle — superficial  in  contradistinction  to  a  still  deeper 
one,  the  <!<'<']>  'u  if  f<i -clavicular  triangle — seen  after  the  removal  of  the  clavi-pectoral 
fascia. 

The  superficial  infra-clavicular  triangle. — The  base  of  the  superficial  infra- 
clavicular  triangle  is  directed  outward  and  is  formed  by  the  anterior  border  of  the 
deltoid  muscle ;  the  apex  is  directed  inward  and  lies  at  the  junction  of  the  clavicle 
with  the  sternum.  It  is  bounded  above  by  the  inner  half  of  the  clavicle,  and 
below  by  the  upper  edge  of  the  sternal  portion  of  the  pectoralis  major.  Its  roof 
is  formed  by  the  clavicular  portion  of  the  pectoralis  major ;  its  floor,  by  the  clavi- 
pectoral  fascia.  The  contents  of  the  space  are  some  fat  and  the  structures  which 
pierce  its  floor — the  cephalic  vein,  the  acromio-thoracic  artery  and  vein,  and  the 
uii'i-iiiit  iiiitrrior  thoracic  nerve. 

The  deep  pectoral  or  clavi-pectoral  fascia  is  attached  above  to  the  lips  of  the 
subclavian  groove  on  the  under  surface  of  the  clavicle.  At  its  attachment  to  the 
clavicle  it  consists  of  two  layers,  which  inclose  the  subclavius  muscle  and  unite 
along  the  lower  border  of  that  muscle  to  form  a  single  layer.  Externally,  it  is 


B8  SURGICAL   ANATOMY 

attached  to  the  upper  surface  of  tin-  coracoid  process;  internally,  it  blends  with 
the  intercostal  fascia  covering  the  upper  two  intercostal  spaces;  below,  it  divides 
along  the  upper  border  of  the  pcctoralis  minor  to  invest  this  muscle.  From  the 
lower  border  of  the  pcctoralis  minor  it  descends  as  a  single  layer  to  join  the  super- 
ficial layer  of  the  deep  or  pectoral  fascia  along  the  lower  margin  of  the  pcctoralis 
major,  forming  the  axillary  fascia.  As  previously  described,  it  forms  the  floor  of 
the  superficial  infra-clavicular  triangle.  It  is  denser  externally  at  its  attachment 
to  the  coracoid  process  than  internally,  where  it  blends  with  the  fascia  covering 
the  first  two  intercostal  spaces.  It  also  blends  with  the  sheath  of  the  axillary 
vessels.  The  clavi-pectoral  fascia  is  sometimes  spoken  of  as  the  xiix/nnaitri/  lii/nnnut 
of  tin  n.rillii,  since  by  its  connection  with  the  fascial  sheath  of  the  pcetoralis  minor 
it  suspends  the  axillary  fascia  (floor  of  axilla),  thus  forming  the  hollow  of  the 
arm-pit. 

The  costo-coracoid  membrane  is  that  portion  of  the  clavi-peetoral  fascia  which 
fills  the  interval  between  the  clavicle  and  upper  border  of  the  pectoralis  minor 
muscle.  It  is  denser  than  the  lower  part  of  the  clavi-pectoral  fascia,  and  is  pierced 
by  the  c^/i/m/ir  rri/i,  acromio-thoracic  artery  and  vein,. the  external  anterior  thorncic 
nerve,  and  sometimes  by  &  branch  of  the  superior  ilmnn-ic  arfn-i/. 

Considerable  importance  attaches  to  the  arrangement  of  the  deep  or  pectoral 
fascia  because  of  possible  purulent  collections  in  this  region.  Such  a  collection 
situated  behind  the  pectoralis  major,  or  between  it  and  the  pectoralis  minor,  would 
point  either  at  the  anterior  border  of  the  axilla  or  under  the  clavicle  in  the  upper 
end  of  the  delto-pectoral  sulcus.  If,  however,  it  were  situated  behind  the  pecto- 
ralis minor  muscle  and  the  deep  layer  of  the  deep  fascia,  it  would  either  remain 
confined  in  the  axillary  space  and  point  at  the  floor  of  the  arm-pit  or  extend 
upward  into  the  neck  in  the  direction  of  least  resistance  and  point  above  the  clavicle. 

DISSECTION. — Divide  the  •  anterior  layer  of  the  clavi-pectoral  fascia  along  its 
attachment  to  the  anterior  lip  of  the  subclavian  groove  of  the  clavicle  and  reflect  it 
downward.  This  will  expose  the  subclavius  muscle. 

The  subclavius  muscle  is  small  and  spindle-shaped.  It  lies  under  the 
clavicle,  over  the  first  rib.  It  arises  by  a  short,  thick  tendon  from  the  first  costal 
cartilage  in  front  of  the  costo-clavicular  (rhomboid)  ligament,  whence  its  fibers  pass 
outward  and  a  little  upward,  to  be  inserted  into  the  subclavian  groove  on  the  under 
surface  of  the  middle  third  of  the  clavicle.  It  is  enveloped  by  the  costo-coracoid 
membrane  and  clavicle.  It  is  at  the  upper  boundary,  therefore,  of  the  two 
infra-clavicular  triangles,  held  between  the  folds  of  that  membrane  which  forms 
part  of  the  floor  of  the  one  and  the  roof  of  the  other.  Above,  it  is  in  close 
relation  with  the  clavicle;  below,  with  the  costo-coracoid  membrane  and  the 
cephalic  vein  ;  in  front,  it  is  in  relation  with  the  clavicular  origin  of  the  pec- 


PLATE  XVIil. 


External    anterior  thoracic  n.- 

Acromio-thoraclc  a. 

Clavicular  branch  of  aero 
Costo-coracoid  rnembran 

Cephalic  v. 

Acromial  branch  of  acromio-thoracic 
Humeral    branch  of  acromio  thoracic  a 
Deltoid  m.. 


thorarir  A  —      . 

Thoracic  branch  of  acromio-thoracic  a 
Chondro-sternal  head  of  pectoralis  major  m. 
Clavicular  head  of  pectoralis  major  m. 
vl_atissimus  dorsi  m. 
ong  head  of  triceps  m. 
Coraco-brachialis  m. 
Short  head  of  biceps  m. 
Long  head  of  biceps  m. 

SUPERFICIAL  INFRACLAVICULAR  TRIANGLE. 
70 


PLATE  XIX. 


Axillary  v 

Subclavius  m. 

Axillary  a. 

External  anterior  thoracic  n 

Brachial  plexus  of  nerves 

Clavicular  branch  of  acromio-thoracic  a.- 

Serratus  magnus  m. 

Thoracic  branch  of  acromio-thoracic  a.- 

Internal  anterior  thoracic  n. 

Acromial  branch  of  acromio-thoracic  a 

Subscapularis  m . 

Humeral  branch  of  acromio-thoracic  a. 

Deltoid  m. 


Clavicular  head  of  pectoralis  major  m. 


Chondro-sternal  head  of  pectoralis  major  m 

Internal  an 
Superior  th 
Pectoralis 
Acromio-th 
Cephalic  v. 


terior  thoracic  n 

**^9_ 

Kflt-*"* 

minor  m  , 

tercostal  m.  

OEEP  INFRACLAVICULAR  TRIANGLE. 
71 


SURFACE   A  \.ITOMY   OF   THE   I'TTER   EXTREMITY.  7:: 

tunilis  major  Mini  deltoid  muscles,  the  anterior  lamella  of  the  costo-coracoid  mem- 
brane  being  between ;  and  behind,  with  the  posterior  layer  <>f  the  costo-coracoid 
membrane,  the  subclavian  vessels,  and  hrachial  plexus  of  nerves. 

I'.i.ooh  Srri'LY. — From  the  clavicular  hrancli  of  the  acromio-thomcic  artery. 

Ni:i;vK  Sri-i'LY. — A  filament  from  the  cord  formed  by  the  tit'th  and  sixth 
cervical  nerves. 

ACTION. — It  depresses  the  shoulder  by  pulling  the  clavicle  downward  and 
forward.  It  also  draws  the  clavicle  inward,  holding  the  inner  extremity  of  the 
bone  against  the  sternum. 

J>issK<TioN. — Push  the  suhclavius  muscle  upward  and  divide  the  posterior 
layer  of  the  eosto-coracoid  membrane  ;  then  divide  the  costo-coracoid  membrane  at 
its  attachments  to  the  coracoid  process  and  the  upper  two  intercostal  spaces,  and 
dissect  it  from  the  structures  which  pierce  it,  leaving  the  latter  intact.  This  will 
expose  to  view  the  deep  infra-clavicular  triangle. 

The  deep  infra-clavicular  triangle. — The  base  of  the  deep  infra-clavicular 
triangle  is  directed  inward,  and  is  formed  by  the  line  of  junction  of  the  upper  two 
ribs  with  their  costal  cartilages;  the  apex  is  directed  outward,  toward  the  coracoid 
process.  It  is  bounded  above  by  the  inner  half  of  the  clavicle,  and  below  by  the 
upper  border  of  the  pectoralis  minor.  Its  roof  is  formed  by  the  oosto-coracoid 
membrane  and  its  floor  by  the  upper  two  ribs  and  intercostal  muscles,  the  serratns 
magnns,  and  the  subscapularis  muscle.  It  will  be  seen  that  the  subclavius  muscle, 
since  it  is  ensheathed  by  the  costo-coracoid  membrane,  must  necessarily  be  found 
in  the  floor  of  the  superficial  and  in  the  roof  of  the  deep  infra-clavicular  triangle. 
The  contents  of  the  deep  triangle  are  the  tliinl  jmrtioii  of  tie  a.i'iHnr//  nin.  \}\c  first 
l>»rti»n  of  the  ir.ri//<ii->i  artery,  the  *n/x  rim-  thoracic  and  aeromio-thoracic  mier/ex  a  ml 
veins,  the  terminal  jxiiiivn  of  the  cephalic  rein,  the  e.ilei'nuf  un<l  intei-nul  anterior 
tlim-iicii-  nerves,  the  cords  of  the  axitlm-i/  <>r  ln-<« 7//W  jilcjnx,  and  the  /mx/crim-  <»•  long 
thoracic  nerre.  These  structures  will  be  described  under  the  dissection  of  the 
axilla,  as  they  can  be  studied  to  better  advantage  at  that  time. 

DISSKCTION. — The  remaining  or  chondro-sternal  portion  of  the  pectoralis  major 
should  now  be  severed  in  the  middle  and  reflected,  when  will  be  exposed  the  pecto- 
ral ix  minor  enveloped  by  the  deep  layer  of  the  deep  or  pectoral  fascia.  The  internal 
antfi-ini- thni-iteii'  nerve  should  be  observed  as  it  passes  from  the  pectoralis  minor  to 
the  pectoralis  major.  The  fascia  may  then  be  removed  from  the  pectoralis  minor. 

The  pectoralis  minor  muscle  is  of  an  elongated  triangular  shape,  and  arises 
at  its  base  from  the  anterior  extremities  of  the  third,  fourth,  and  fifth  ribs,  and 
the  intervening  intercostal  fascia.  Its  fibers  pass  upward  and  outward,  to  be 
inserted  by  a  flat  tendon  into  the  anterior  half  of  the  inner  surface  of  the  coracoid 
process  of  the  scapula  and  the  upper  part  of  the  tendon  of  the  coraco-brachialis 


71  SURGICAL   A  \.\TDMY. 

muscle.  It  lies  behind,  and  in  contact  with,  tlic  pectoralis  major,  between  (lie 
two  lamella1  of  the  deep  layer  of  the  pectoral  fascia,  and  immediately  in  front 
of  the  axillary  contents.  Its  upper  and  lower  margins  divide  the  axillary  artery, 
over  which  it  passes,  into  three  parts,  the  first  portion  being  above,  the  second 
behind,  and  the  third  below,  the  muscle.  It  is  supplied  by  the  superior  or 
short  thoracic  and  long  thoracic  arteries,  which  pass  along  its  upper  and  lower 
border*  respectively. 

It  receives  its  NKKVK  Sri'i'i.Y  from  the  internal  anterior  thoracic  nerve,  which 
pierces  it  to  enter  the  under  surface  of  the  pectoralis  major. 

ACTION. — It  draws  the  shoulder  downward  and  forward,  but  does  not  draw 
it  inward,  as  is  so  generally  stated,  because,  though  tending  to  do  so,  the  clavicle 
prevents.  If  the  shoulder  were  fixed  well  forward,  it  could  act  as  a  powerful 
inspiratory  muscle. 

DISSECTION. — This  muscle  should  now  be  severed  through  its  middle  and 
reflected  as  far  as  its  attachments,  thus  exposing  the  whole  axilla  to  view.  Upon 
the  opposite  side  of  the  body  the  axillary  contents  should  be  dissected  from  below 
upward  without  disturbing  the  pectoral  muscles,  access  to  (lie  axilla  being  gained 
through  its  base,  which  is  the  axillary  fascia.  It  is  by  this  latter  route  that  the 
surgeon  enters  in  nearly  all  axillary  operations.  The  study  of  the  axillary  eon- 
tents  from  these  two  different  directions  forms  the  best  method  of  practically 
familiari/ing  the  student  with  their  intricate  relations. 

The  axillary  fascia. — The  layer  of  fascia  inclosing  the  pectoralis  minor 
joins  the  layer  covering  the  pectoralis  major  along  the  lower  or  axillary  border  of 
the  latter  muscle  ;  by  this  union  is  formed  the  axillary  fascia.  It  is  a  dense  mem- 
brane which  extends  from  the  lower  border  of  the  pectoralis  major  backward  to  the 
latissimus  dorsi  muscle,  and  forms  the  floor  of  the  axilla — outward  to  become  con- 
tinuous with  the  deep  fascia  of  the  arm,  and  inward  to  blend  with  the  deep  fascia 
of  the  chest.  Where  it  meets  the  latissimus  dorsi  (posterior  border  of  the  axilla),  it 
divides  into  two  layers,  which  ensheath  that  muscle  and  become  continuous  with 
the  deep  fascia  of  the  back. 

The  axilla,  or  arm-pit,  is  a  pyramidal-shaped  space  or  recess,  situated  between 
the  upper  part  of  the  side  of  the  chest  and  the  upper  part  of  the  arm.  It  has  a 
base,  an  apex,  and  four  sides  or  walls.  The  base  directed  downward  between  the 
free  borders  of  the  pectoralis  major  muscle  in  front  and  the  tcres  major  and  latis- 
simus dorsi  behind,  is  formed  by  the  axillary  fascia.  These  borders  are  known  as 
the  anterior  and  the  posterior  folds  of  the  axilla.  The  apex,  to  the  inner  side  of 
the  coracoid  process  and  directed  upward,  is  bounded  by  the  clavicle,  the  first  rib, 
and  the  upper  margin  of  the  scapula.  Through  the  apex,  which  is  the  point  of 
communication  between  the  neck  and  axilla,  pass  the  axillary  vessels,  the  brachial 


PLATE  XX. 


Alar  tn 

Long  thoracic  a 

Outer  cord  of  brachial  plexus 

:ord  of  brachial  plexus  (displaced* 
Pectoralis  minor  m. 

Musculo-cutaneous  n. 
Subscapular  a. 
Circumflex  n. 
Posterior  circumflex  a. 
Coraco-brachialis  m.- 
Dorsalis  scapuii  a 


Acromio-thoracic  a. 
Suprascapular  n. 

taternal  anterior  thoracic  n. 
External  anterior  thoracic  n, 
•ry  a. 

Xrllary    v. 

Subclavius  m. 
Superior  thoracic  a. 


,Clavicular  head  of 
pectoralis  major  m. 


Short  head 
of  biceps  m 


Anterior  circumflex  a 
Lower  subscapular  n 
Median  n.  - 
Deltoid  m 


Triceps  m 
Dinar  n. 

Musculo-spiral  n. 
Lesser  internal  cutaneous 
Teres  major  m 
Long  subscapular  n. 
Subscapularis  m. 
Subscapular  a. 

Posterioror  long  thoracic  n. 
Latissimus  dorsi  m. 


Intercosto-humeral  n. 
Dictation  of  serratus  magnus  m. 


Pectoralis  minor  m, 
Chondro-sternal  head  of  pectoralis  major 


CONTENTS  OF  AXILLA  SHOWN  BY  DISSECTION   MADE  FROM  BEFORE  BACKWARD 

76 


PLATE  XXI. 


CONTENTS  OF  AXILLA  SHOWN  BY  DISSECTION  MADE  FROM  BELOW  UPWARD, 

77 


SURFACE   ANATOMY   <>!•'   Till-:   r/V'AV,'    KXTllKMITY.  7!) 

plexus  of  nerves,  and  the  posterior  or  long  thoracic  nerve  (external  respiratory 
nerve  of  Hell).  The  anterior  wall  of  the  axilla  is  formed  by  the  pectoral  and 
sulicliivius  muscles  and  the  clavi-pectoral  fascia,  and  the  ]n>sterior  by  the  siib- 
scapular,  the  teres  major,  and  the  latissimus  dorsi  muscle.  Kxternally  the 
anterior  and  posterior  walls  converge.  Tin-  inner  wall  is  formed  l>y  the  four 
or  live  upper  ribs,  the  intervening  intercostal  muscles,  and  the  corresponding 
(limitations  of  the  serralus  magnus;  the  outer  wall  is  formed  by  the  humerus, 
the  short  head  of  the  biceps,  and  the  coraco-brachialis  muscle.  The  axillary 
vessels  and  nerves  are  in  intimate  relation  with  the  outer  wall  of  the  axilla, 
and  this,  therefore,  is  the  most  important  part  of  the  space. 

The  axilla  varies  in  depth  according  to  the  relation  of  the  arm  to  the  side  of  the 
chest.  It  is  deepest  when  the  arm  is  raised  at  an  incline  of  about  forty-five  degrees, 
and  shallowest  when  the  arm  is  strongly  abducted.  In  the  position  of  strong 
abduction  of  the  arm  its  contents  are  brought  nearer  the  surface,  and  this  position, 
therefore,  is  the  one  preferred  when  operating  upon  the  axilla.  When  palpating 
the  axilla  to  determine  the  position  of  the  head  of  the  humerus,  the  presence  or 
absence  of  enlarged  glands,  etc.,  the  arm  should  be  brought  near  the  side,  thus 
relaxing  the  axillary  fascia  and  allowing  it  to  be  carried  in  advance  of  the  finger, 
thereby  facilitating  the  examination. 

A  colld-linn  nf  jinx  within  the  axilla,  if  not  afforded  an  ample  and  thorough 
outlet,  is  more  likely  to  point  in  the  neck  than  at  the  base  of  the  axilla,  as  it  would 
meet  with  less  resistance  in  traveling  by  way  of  the  apex  of  the  space  than  in 
ulcerating  through  the  axillary  fascia.  Axillary  abscess  may  be  secondary  to 
abscess  of  the  neck,  owing  to  the  rather  free  communication  between  the  neck  and 
the  axilla.  (For  the  course  taken  by  purulent  collections  beneath  the  pectoral 
muscles  and  not  within  the  axilla,  proper,  see  description  of  the  arrangement  of  the 
layers  of  the  deep  or  pectoral  fascia,  p.  G3.)  When  opening  the  axilla  from  below 
for  the  purpose  of  giving  exit  to  a  purulent  or  other  collection,  the  incision  should 
be  made  midway  between  the  anterior  and  posterior  folds,  and  from  without  inward, 
away  from  the  large  blood-vessels  and  nerves  which  lie  along  its  outer  wall.  The 
incision  must  not  be  carried  too  far  inward,  for  fear  of  wounding  the  posterior 
thoracic  nerve,  which  lies  along  the  inner  wall  of  the  axilla — an  accident  which 
would  likely  he  followed,  if  the  nerve  were  completely  severed,  by  paralysis  of  the 
serratus  magnus  muscle.  Again,  by  confining  the  incision  to  the  center  of  the 
axilla,  the  long  thoracic  artery  (deep  external  mammary)  on  the  anterior  wall, 
and  the  subscapular  vessels  and  long  subscapular  nerve  on  the  posterior  wall,  of 
the  axilla  will  be  avoided.  The  incision  may  divide  the  superficial  external 
mammary  artery  which,  when  present,  runs  through  the  superficial  fascia  over- 
lying the  axillary  fascia.  This  vessel,  if  divided,  may  give  rise  to  enough 


80  SURGICAL   .\\.\TOMY. 

bleeding  to  alarm  the  operator  and  lead  him  to  fear  that  lie  has  wounded  a 
large  hraneh  within  the  axilla. 

The  mutt-nix  of  the  axilla  are  the  axillary  vein  and  its  branches;  the  axillary 
artery  and  its  l>nmehes;  the  axillary  or  hraehial  plexus  of  nerves,  and  most  of  its 
liranehes  ;  the  lateral  eutaneons  hranehes  of  the  intercostal  nerves,  that  of  ihr 
second  being  known  as  the  intercosto-huiueral  ;  the  posterior  or  long  thoracic 
nerve  :  three  chains  of  axillary  lymphatic  glands,  and  a  large  quantity  of  areolar 
tissue  and  fat. 

DISSKITION. — Fpon  the  side  of  the  body  on  which  the  anterior  axillary  wall 
has  been  rellected  the  areolar  tissue  and  fat  should  he  removed  from  the  other 
structures  in  the  axilla  in  the  order  in  which  they  have  heen  enumerated,  while 
upon  the  opposite  side  the  space  should  he  dissected  from  lielow  upward. 

The  axillary  vessels  are  inclosed  by  a  xJiratii  derived  from  the  prevertehral 
layer  of  the  deep  cervical  fascia,  the  anterior  wall  of  which  is  reinforced  hy  the 
eosto-eoracoid  memhraiie.  The  sheath  should  he  removed  in  order  that  the 
vessels  may  he  more  clearly  exposed. 

The  axillary  vein,  the  vessel  accompanying  the  axillary  artery,  is  the  con- 
tinuation of  the  hasilic  vein.  It  commences  at  the  lower  horder  of  the  tendon 
of  the  teres  major  and  passes  upward  along  the  outer  wall  of  the  axilla  as  far 
as  the  lower  horder  of  the.  first  rih,  where  it  becomes  the  subclavian  vein.  It 
lies  to  the  inner  or  thoracic  side  of  the  axillary  artery.  The  axillary  vein 
receives  the  cephalic  vein  and  branches  corresponding  to  those  of  the  axillary 
artery,  with  the  exception  of  those  of  the  circumtlex  arteries,  which  may  enter 
either  the  subscapular  vein  or  one  of  the  vena3  comites  of  the  brachial  artery, 
or  the  cephalic  vein.  In  the  upper  part  of  the  axilla  the  relation  between  the 
axillary  vein  and  the  axillary  artery  is  more  intimate  than  it  is  in  the  lower 
part.  (See  Belations  of  the  Axillary  Artery,  p.  82.)  The  axillary  vein,  like 
the  artery,  may  be  said  to  consist  of  three  portions — namely,  the  first,  the  second, 
and  the  third.  The  first  and  third  portions  of  the  vein  correspond  to  the 
third  and  first  portions  of  the  artery  respectively. 

The  axillary  vein  is  more  likely  to  be  wounded  than  the  axillary  artery,  as  it 
lies  nearer  the  surface.  AVhen  the  vein  is  engorged  with  blood,  it  sometimes  comes 
into  sight  sooner  than  we  expect ;  and  therefore  it  behooves  the  operator  to  be  very 
careful.  On  account  of  the  size  of  the  axillary  vein  and  its  close  proximity  to  the 
heart,  in  wounds  of  the  vessel  there  is  danger  of  air  entering  the  circulation.  The 
adherence  of  the  costo-coracoid  membrane  to  the  sheath  of  the  vessel,  and  of  the 
sheath  in  turn  to  the  wall  of  the  vein,  favors  the  maintenance  of  an  uncollapsed 
condition  of  the  vessel.  Notwithstanding  that  experiments  have  been  made  to 
demonstrate  that  air  can  be  injected  into  the  circulation  without  producing  any 


SURFACE  AXATOMY   o/-'   THE   ITI'I-I;    KXTIiKMlTY.  *1. 

deleterious  cH'ccts,  it  is,  nevertheless,  better  to  err  on  the  side  of  safety  :  conse- 
quently, when  large  venous  trunks  are  divided,  as  in  amputation,  they,  as  well  as 
the  arteries,  should  lie  separately  limited.  The  danger  in  including  the  artery  and 
the  vein  in  the  same  ligature  is  the  establishment  of  an  nleerative  communication 
lietween  the  vessels,  and  a  eonsei |iieiit  a rterio-veiious  aiH'urysm.  Again,  the 
divided  vein,  when  not  tied,  oilers  an  avenue  tor  the  introduction  of  septic 
matter  into  the  eilvulalioii. 

Pressure  upon  the  axillary  vein,  as  in  forward  dislocation  of  the  liumerus, 
from  axillary  tumors,  a  crutch,  an  axillary  pad,  or  enlargement  of  the  lym- 
phatic glands,  may  cause  edema  of  the  arm  and  forearm.  Kdema  of  the  arm 
associated  with  carcinoma  of  the  breast  is  a  grave  symptom,  because  it  indicate.* 
involvement  of  the  deep  lymphatics,  which  are  in  relation  with  the  axillary  vessels. 
Kdeina  appearing  shortly  after  removing  the  fat  and  lymphatics  of  the  axilla 
in  excision  of  the  breast  is  due  to  a  phlebitis,  or  loss  of  support  previously  given 
the  vein  by  the  fat,  lymphatics,  and  pectoral  muscles. 

When  opening  the  arm-pit  for  the  purpose  of  excising  a  growth  or  removing 
enlarged  glands,  the  incision  T  recommend  is  one  made  along  the  center  of  the 
arm-pit,  extending  far  enough  into  the  arm  to  expose  the  first  portion  of  the 
axillary  vein.  The  dissection  should  then  be  made  from  without  inward  or 
away  from  the  axillary  vein.  IVv  following  this  method  there  will  be  less  risk 
of  wounding  the  vein  than  when  working  from  within  outward  or  from  below 
upward.  The  practice  of  removing  enlarged  glands  with  the  finger,  used  as  a 
hook,  through  a  comparatively  small  opening  in  the  base  of  the  axilla  is 
dangerous. 

The  axillary  artery,  the  continuation  of  the  subclavian,  commences  at  the 
lower  border  of  the  first  rib.  It  passes  downward  and  outward  through  the  apex, 
along  the  outer  wall  of  the  axilla,  beneath  the  greater  and  lesser  pectoral  muscles, 
and  along  the  inner  border  of  the  coraco-brachialis  to  the  lower  border  of  the 
tendon  of  the  teres  major,  where  it  becomes  the  brachial.  The  course  of  the  vessel 
through  the  axilla  varies  with  the  relation  of  the  arm  to  the  body.  With  the 
arm  abducted  to  a  right  angle  with  the  body  the  artery  takes  an  almost  straight 
course,  indicated  by  a  line  drawn  from  a  point  a  little  to  the  inner  side  of  the 
center  of  the  clavicle  to  the  inner  side  of  the  tendon  of  the  biceps  at  the  middle 
of  the  bend  of  the  elbow  ;  with  the  arm  carried  well  upward  the  artery  describes 
a  curve  the  concavity  of  which  is  directed  toward  the  shoulder ;  with  the  arm  at 
the  side  the  artery  describes  a  curve  the  convexity  of  which  is  directed  toward  the 
shoulder. 

Pressure  upon  the  axillary  artery,  as  in  forward  dislocation  of  the  humerus, 
may  cause  absence  of  the  radial  pulse. 


82  SURGICAL   ANATOMY. 

As  the  relations  of  the  artery  vary  in  passing  through  (lie  axilla,  it  is,  for 
convenience  of  description,  divided  into  three  portions — the  first,  second,  and 
third. 

The  first  portion  extends  from  the  lower  border  of  the  first  rib  to  the  upper 
border  of  the  pectoralis  minor;  the  x«-<tn<l  jmrtimi.  the  shortest,  lies  behind  that 
muscle;  the  tliinl  portion,  the  longest,  extends  from  the  lower  border  of  the  pec- 
toralis minor  to  the  lower  border  of  the  tendon  of  the  teivs  major.  This  last 
portion  of  the  artery,  as  it  is  most  accessible,  is  known  as  the  point  of  election  for 
ligatiou,  and  a  ligature  applied  to  this  part  <>f  the  vessel  can  be  made  to  encircle 
it  further  away  from  the  branches  than  in  either  the  first  or  second  portions, 
and  thereby  interfere  less  with  the  establishment  of  the  collateral  circulation. 
This  portion  of  the  vessel  oilers  a  favorable  point  for  digital  compression  against 
the  upper  end  of  the  hnmerns  or  with  the  linger  inserted  into  the  axilla,  against 
the  axillary  or  external  margin  of  the  scapula.  A  muscular  slip,  passing  from 
the  latissimus  dorsi  to  join  the  pectoralis  major,  coraco-brachialis,  or  biceps 
muscle,  and  crossing  the  third  portion  of  the  axillary  artery,  is  sometimes  present. 
This  should  be  borne  in  mind,  and  the  slip  should  not  be  mistaken  for  the  coraco- 
brachialis. 

THE  FIRST  PORTION. — In  front  of  this  portion  are  the  external  anterior 
thoracic  nerve,  the  costo-coracoid  membrane,  the  cephalic  vein,  the  acroinio-thoracic 
vessels,  the  axillary  lymphatic  trunk,  and  the  clavicular  head  of  the  pectoralis 
major;  to  the  inner  side  and  overlapping  it  when  the  arm  is  at  the  side 
of  the  body  is  the  axillary  vein  ;  when  the  arm  is  abducted  to  a  right  angle 
with  the  body,  the  vein  lies  entirety  to  the  inner  side  of  the  artery  ;  to  the 
outer  side  is  the  brachial  plexus ;  behind  is  the  first  intercostal  muscle,  the 
first  digitation  of  the  serratus  magnns,  and  the  posterior  thoracic  nerve.  It 
is  important  to  remember  the  relation  between  the  vein  and  artery  when  ligating 
the  first  portion  of  the  latter.  Its  ligation  may  be  beset  with  difficulties 
additional  to  its  depth  and  its  varying  relations  to  its  companion  vein.  The 
causes  of  these  are  the  occasional  entrance  of  the  cephalic  into  the  subclavian 
vein,  thereby  crossing  the  artery  at  a  higher  point,  the  presence  of  the  envelop- 
ing plexus,  formed  by  the  external  and  internal  anterior  thoracic  nerves,  the 
artery  being  crossed  by  one  of  the  roots  of  the  median  nerve  (Holden)  or 
by  the  supra-scapular  vein  which  joins  the  axillary  instead  of  the  external 
jugular.  The  brandies  of  this  portion  are  the  superior  thoracic  and  the  acromio- 
thoracic. 

The  superior  thoracic  artery  is  the  first  branch  01  the  axillary,  arising  so  close 
to  the  lower  margin  of  the  first  rib  that  it  may  almost  as  well  be  considered,  as  by 
some  anatomists  it  is,  the  last  branch  of  the  subclavian.  At  times  it  is  derived 


PLATE  XXII. 


Branch  of 
Acromio-thoracic  a. 


Posterior  scapular  a. 


Branch  of 

posterior  circumflex  a. 


Subscapular  a. 

Suprascapular  a. 
Dorsalis  scapulae  a 


ANASTOMOSES  OF  ARTERIES  AROUND  THE  SCAPULA. 
84 


SURFACE  A.\.\TOMY   or   Till-:   r/'/'/vA'    EXTHKUITY.        .  85 

from  tlie  aeromio-thoracic.  It  runs  along  tin.-  upper  border  of  the  pectoralis 
minor  to  supply  both  pectoral  muscles,  the  serratus  magnus,  and  the  contents  of 
the  adjacent  inlcreustal  spaces.  It  anastomoses  with  the  intercostal  arteries. 

The  acromio-thoratie  niii  /•;/  is  a  short  trunk,  or  axis,  springing  from  the  axillary 
artery  jusl  ahove  the  upper  margin  of  the  pcctoralis  minor.  It  gives  oil'  three 
divergent  branches — the  thoracic,  the  acromial.  and  the  descending  or  humeral — and 
;;udl  twig  (clavicular  branch)  to  the  subclavins  muscle.  The  thorarir  hriitii-lirx 
(two  or  three)  go  lo  the  pectoral  and  serratus  magnus  muscles,  and  anastomose 
with  the  intercostal  arteries  and  the  intercostal  branches  of  the  internal  mam- 
mary. The  iici-nniiii/  l>i-<i  Hi-lux  pass  outward  over  the  coracoid  process  and  under 
the  deltoid  to  the  top  of  the  acromion,  supplying  the  tissues  of  this  region. 
They  anastomose  with  the  supra-scapular  and  anterior  and  posterior  circumflex 
arteries,  and  form  the  acromial  ivte.  The  iliwitiliitr/  or  Jnoiicral  brmtch  passes 
down  the  delto-pectoral  sulcus  in  relation  with  the  cephalic  vein  to  supply 
the  deltoid  ami  pectoralis  major  muscles.  It  anastomoses  with  the  anterior  and 
posterior  circumflex  arteries.  The  vena  comitet  o/' //«»•  branches  usually  empty  into 
the  cephalic,  hut  sometimes  into  the  axillary  vein. 

THI;  SKCOND  I'OUTIOX. — In  front  of  this  portion  are  the  pectoralis  major  and 
minor  muscles;  to  the  inner  side  are  the  inner  cord  of  the  axillary  plexus  and  also 
the  axillary  vein,  the  latter  lying  a  little  anterior  to  the  artery,  but  separated  from 
it  by  the  nerve  cord  ;  to  the  outer  side  is  the  outer  cord  of  the  plexus;  behind  is 
the  posterior  cord  of  the  plexus  and  the  subscapnlar  muscle,  from  which  both  the 
artery  and  the  nerve  cord  are  separated  by  a  quantity  of  areolar  and  fatty  tissue. 
Its  In-inic/itf!  are  the  alar  thoracic  and  the  long  thoracic. 

The  (i/iir  tliorm-ir  i/rtiri/  is  a  small  branch  distributed  to  the  glands  and  the 
areolar  tissue  of  the  axilla.  As  a  separate  branch  it  is  very  often  absent,  in  which 
event  its  place  is  taken  by  branches  of  one  of  the  other  thoracic  arteries. 

The  mfci'iiir  or  /«/<//  flinrnric  (deep  external  mammary)  artery  runs  down- 
ward and  inward  along  the  lower  border  of  the  pectoralis  minor  to  the  side  of  the 
chest.  It  supplies  the  pectoral  and  serratus  magnus  muscles  and  the  mam- 
mary gland,  and  anastomoses  with  the  superior  thoracic,  intercostal,  and  internal 
mammary  arteries. 

THK  THIRD  PORTION. — In  front  of  the  upper  part  of  this  portion  are  the 
superficial  and  deep  fascia  and  the  pectoralis  major,  while  the  lower  part  is 
only  covered  by  skin,  superficial  and  deep  fascia.  In  front  of  this  part  of  the 
artery  are  the  inner  head  of  the  median  nerve  and  the  internal  cutaneous  nerve  ; 
to  the  inner  side  are  the  ulnar  nerve,  the  axillary  vein,  and  the  lesser  internal 
cutaneous  nerve,  the  latter  being  separated  from  the  artery  by  the  vein  ;  to  the 
outer  side  are  the  median  and  musculo-cutaneous  nerves  and  the  coraco-brachialis 


si;  SURGICAL   .I.Y.I  T< >.MY. 

muscle;  wliile  behind  it  are  the  nmsrulo-spiral  and  circumflex  nerves,  the  sub- 
scapularis  muscle,  and  the  tendons  of  the  latissinms  dorsi  and  tcivs  major.  Ils 
branches  arc  the  subscapular,  anterior  circumflex,  and  ] ulterior  circumflex. 

The  subscapular  »/•/</•//.  (lie  largest  branch  of  the  axillary,  arises  opposite  the 
outer  or  axillary  border  of  the  snbscapular  muscle.  It  runs  inward  and  downward 
along  this  border  to  the  inferior  angle  of  Hie  scapula,  where  it  anastomoses  with 
the  posterior  scapular,  the  larger  of  the  two  terminal  branches  of  the  transver.-alis 
colli.  It  also  anastomoses  with  the  long  thoracic  and  the  intercostal  arteries.  It 
is  accompanied  in  the  lower  portion  of  its  course  by  the  long  subscapular  nerve. 
In  its  course  it  gives  branches  to  the  subscapularis,  serratus  magnus,  latissimus 
clorsi,  and  teres  major  muscles,  and  to  the  glands  and  areolar  tissue  of  the  axilla. 
A  short  distance  below  its  origin  it  gives  off  a  large  branch,  the  <lnrx<il!x  scapulse, 
which  winds  around  the  axillary  border  of  the  scapula  between  the  snhscapularis 
and  teres  minor,  passing  through  the  triangular  subdivision  of  that  general 
triangular  space,  situated  at  the  axillary  border  of  the  scapula,  to  the  dorsum 
of  this  bone,  where  it  anastomoses  with  the  supra-scapular  and  posterior  scapular 
arteries.  The  space  through  which  it  passes  is  bounded  by  the  subscapularis  and 
teres  minor,  the  teres  major,  and  the  long  head  of  the  triceps.  A  small  branch 
is  given  off  from  the  dorsalis  scapula;  which  enters  the  subscapular  fossa  beneath 
the  subscapular  muscle.  The  terminal  part  of  the  dorsalis  scapula-  will  be  seen 
when  dissecting  the  infra-spinous  region  of  the  scapula.  A  line  drawn  along  the 
axillary  border  of  the  scapula  to  its  inferior  angle  will  indicate  the  course  of  the 
subscapular  artery. 

The  subscapular  triangle,  the  general  triangular  space  already  mentioned,  is 
bounded  above  by  the  subscapular  and  teres  minor  muscles,  below  by  the  teres 
major,  and  on  the  outer  side  by  the  surgical  neck  of  the  luinierus.  This  space  is 
subdivided,  by  the  long  head  of  the  triceps,  into  the  triangular  space  proper, 
through  which  pass  the  dorsalis  scapulae  vessels,  and  the  quadrangular  space, 
through  which  pass,  as  will  be  seen  later,  the  posterior  circumflex  vessels  and  the 
circumflex  nerve. 

The  posterior  circumflex,  much  the  larger  of  the  two  circumflex  arteries, 
arises  from  the  posterior  aspect  of  the  axillary  artery,  below  the  lower  border  of 
the  subscapular  muscle.  Accompanied  by  its  veins  and  the  circumflex  nerve,  it 
passes  backward  through  the  quadrangular  subdivision  of  the  subscapular  triangle. 
It  winds  around  the  surgical  neck  of  the  humerus  to  reach  the  under  surface  of  the 
deltoid  muscle,  to  which,  together  with  the  shoulder-joint,  it  is  distributed.  It 
anastomoses  with  the  acromio-thoracic,  the  supra-scapular,  the  subscapular,  the 
anterior  circumflex,  and  the  ascending  branch  of  the  superior  profunda.  The 
posterior  circumflex,  when  not  a  branch  of  the  axillary,  may  spring  from  the 


PLATE  XXIII. 


Eighth  cervical  nerve 
Seventh  cervical  nerves 
Nerves  to  scaleni  and  Longus  colli 

Sixth  cervical  n. 
Nerves  to  scaleni  and  Longus  colli. 

Fifth  cervical  n. 
From  fourth  cervical  n. 
Roots  of  phrenic  n.         \ 
N.  to  subcl  j .   tis 
Rhomboid  n. 


N.  to  Levator  anguli  Scapn    le 

Sup:  iscapul    i    i.  \ 

Upper  subscapular  n. 


External  anterior  thoracic  n 

\ 
Internal  anterior  thoracic  n.  \ 


Muscu 
Circun 


Nerves  to 
Scaleni  and 
Longus  colii 


First  thoracic  n 


intercostal  n. 


Median  n 


AXILLARY  OR  BRACHIAL  PLEXUS  OF  NERVES. 
87 


SURFACE   ANATOMY   OF  T11K   I'lTKl!    A'.Y '/'/,' /-;.J//7T.  si) 

brachial,  or  superior  profunda,  or  it  may  arise  from  the  axillary  as  a  (-(1111111(111 
trunk  with  the  suhscapular. 

The  anterior  circumflex  artery  arises  from  the  outer  aspect  of  the  axillary, 
runs  outward  over  the  tendon  of  the  latii-simus  dorsi  and  beneath  the  coraco- 
brachialis  and  the  short  head  of  the  biceps,  and  over  the  surgical  neck  of  the 
humerus  to  the  under  surface  of  the  deltoid,  which  it  .supplies.  In  excision  of 
the  shoulder-joint  this  artery  is  often  difficult  to  ligate,  as  it  lies  close  to  the 
lidiie.  A  small  branch,  the  /iiri]>it<i/.  is  given  off  from  the  anterior  ciivumltex 
where  it  crosses  the  bicipital  groove.  This  branch  passes  up  the  groove  with  the 
long  tendon  of  the  biceps  and  supplies  the  shoulder-joint  and  the  head  of 
the  humerus.  The  anterior  circumflex  anastomoses  with  the  posterior  circum- 
flex and  the  acromio-thoracic. 

The  axillary  or  brachial  plexus  of  nerves  in  the  neck  cou>ists  of  three 
trunks — an  upper,  a  middle,  and  a  lower;  in  the  axilla,  of  three  cords — an 
outer,  an  inner,  and  a  posterior.  The  plexus  is  formed  by  the  anterior  divisions 
of  the  lower  four  cervical  nerves  and  first  dorsal  nerve.  The  three  trunks,  seen 
iu  the  deep  dissection  of  the  side  of  the  neck,  are  formed  as  follows :  The 
anterior  primary  divisions  of  the  fifth  and  sixth  cervical  nerves  form  the  upper 
trunk,  the  anterior  primary  divisions  of  the  eighth  cervical  and  first  dorsal  nerve 
form  the  lower  trunk,  and  the  anterior  primary  division  of  the  seventh  cervical 
forms  the  middle  trunk.  These  trunks  lie  in  relation  with  the  second  and  third 
portions  of  the  subclavian  artery.  The  upper  and  middle  trunks  lie  above  the 
artery,  while  the  lower  is  partly  behind  it. 

These  three  trunks  enter  the  axilla  by  way  of  its  apex,  lying  above  and  to  the 
outer  (acromial)  side  of  the  first  portion  of  the  axillary  artery.  Each  trunk  divides 
into  an  anterior  and  a  posterior  branch.  The  anterior  branches  form  the  outer 
and  inner  cords  of  the  plexus,  while-  the  posterior  branches  form  the  posterior 
cord.  The  anterior  branches  of  the  upper  and  middle  trunks  unite  to  form  the 
outer  cord,  which  lies  on  the  outer  side  of  the  second  portion  of  the  axillary 
artery  ;  the  anterior  branch  of  the  lower  trunk  constitutes  the  inner  cord  of  the 
plexus,  which  lies  on  the  inner  side  of  the  artery  ;  the  posterior  branches  of  all 
three  trunks  unite  to  form  the  posterior  cord  of  the  plexus,  which  lies  behind  the 
second  portion  of  the  axillary  artery.  Where,  as  occasionally  happens,  the  poste- 
rior cord  is  formed  simply  by  the  union  of  the  posterior  branches  of  the  upper  and 
middle  trunks,  the  posterior  branch  of  the  lower  trunk,  small  in  comparison  with 
tin  others,  unites  with  the  musculo-spiral  branch  of  the  posterior  cord. 

Pressure  upon  the  brachial  plexus  maybe  produced  by  an  axillary  tumor, 
an  axillary  aneurysm,  an  anterior  luxation  of  the  humerus,  a  fracture  of  the 
clavicle,  a  crutch,  or  an  axillary  pad  in  the  treatment  of  fracture  of  the  humerus. 


!>o  SURGICAL   .\\.\To.MY. 

The  pressure  causes  tingling,  numbness,  and  pain  in  the  upper  extremity,  and 
sometimes  ]>;ir;ilysis  of  some  ol  the  muscles  of  this  part  of  the  body. 

The  In-intclit x  given  otl'  from  the  axillary  plexus  he-low  the  clavicle  are  the 
external  and  internal  anterior  thoracic,  the  three  subscapular,  the  circumtlex,  the 
musculo-cutaneous  or  external  cutaneous,  the  median,  the  ulnar.  the  internal  cuta- 
neous, the  lesser  internal  cutaneous,  and  the  musculo-spiral.  Of  these  branches  the 
external  anterior  thoracic,  the  outer  head  of  the  median,  and  the  musculo-cutaneous 
arise  from  the  outer  cord  ;  the  subscapular,  the  circumtlex.  and  the  musculo-spiral 
from  the  posterior  cord;  and  the  inner  head  of  the  median,  the  ulnar.  the  internal 
cutaneous,  the  lesser  internal  cutaneous,  ami  the  internal  anterior  thoracic  from 
the  inner  cord. 

The  external  or  superficial  anterior  thoracic  nerve  is  derived  from  the  begin- 
ning of  the  outer  cord,  just  below  the  clavicle,  passes  inward  across  the  axillary 
vessels,  and  pierces  the  costo-coracoid  membrane  to  enter  the  under  surface  of  the 
pectorulis  major  to  supply  it.  It  communicates  with  the  internal  anterior  thoracic 
nerve. 

The  internal  or  deeper  anterior  thoracic  nerve,  smaller  than  the  external,  is 
derived  from  the  inner  cord,  just  helow  the  clavicle,  and  passes  forward  between 
the  axillary  artery  and  vein,  sometimes  piercing  the  sheath  of  the  latter.  It  enters 
the  peetoralis  minor,  to  which  it  gives  branches,  and  then  pierces  it  to  enter  the 
pectoi-alis  major.  It  gives  off  a  branch  which  forms,  with  a  branch  from  the 
external  anterior  thoracic  nerve,  a  loop  around  the  inner  side  of  the  axillary 
artery,  from  which  loop  pass  other  branches  to  enter  the  peetoralis  major. 

The  three  subscapular  nerves — the  upper,  the  middle,  and  the  lower — arise 
from  the  posterior  cord.  The  upper  or  short  subscapular  supplies  the  upper  part 
of  the  subscapular  muscle ;  the  middle  or  long  subscapular  accompanies  the  sub- 
scapular  artery  and  supplies  the  latissinms  dorsi  muscle;  the  lower  subscapular 
supplies  the  axillary  border  of  the  subscapular  muscle  and  the  teres  major  muscle. 

The  circumflex  nerve  arises  from  the  posterior  cord,  passes  downward  and 
outward  behind  the  third  portion  of  the  axillary  artery,  and  over  the  subscapular 
muscle  to  the  quadrangular  subdivision  of  the  subscapular  triangle,  by  way 
of  which,  in  company  with  the  posterior  circumflex  artery,  it  leaves  the  axilla. 
Between  the  axillary  border  of  the  scapula  and  the  teres  minor  it  gives  off  an 
articular  branch  which  pierces  the  capsular  ligament  to  supply  the  shoulder- 
joint,  after  which  it  divides  into  a  superior  and  an  inferior  branch.  The  xujH'rinr 
branch  accompanies  the  posterior  circumflex  artery  around  the  back  of  the  surgical 
neck  of  the  humerus  and  under  the  deltoid  to  its  anterior  border,  supplying  this 
muscle  and  the  skin  over  its  lower  part.  The  infirim-  brnncl*  sends  twigs  to  the 
back  part  of  the  deltoid,  and  one, -with  a  gangliform  enlargement,  to  the  teres 


SURFACE  A* ATOMY   <>F   THE   I'l'I'Mt   EXTHEMtTY.  !M 

minor,  after  which  it  passes  under  the  deltoid  and  around  the  lower  part  of  its 
posterior  border  lo  supply  the  skin  over  the  long  head  of  the  trieeps  and  the  lower 
two-thirds  of  the  posterior  part  of  the  deltoid.  A  fiiri/iitul.  In-tnn-1/  arises  from  the 
end  of  the  ehvumflex  nerve  and  passes  up  the  hieipital  groove  to  supply  the 
tendon  of  tlie  long  head  of  the  hiceps,  the  upper  end  of  the  humerns,  and  the 
shoulder-joint. 

The  musculo-cutaneous  or  external  cutaneous  nerve  is  the  continuation  of 
the  onter  eord.  It  begins  opposite  the  lower  border  of  the  peetoralis  minor,  lying 
close  to  the  outer  gide  of  the  axillary  artery.  It  then  passes  outward  and  down- 
ward to  the  eoraeo-braehialis  muscle,  which  it  pierces  and  supplies,  undergoing 
subdivision  in  its  substance. 

The  median  nerve  is  formed  at  the  outer  side,  or  in  front,  of  the  third  portion 
of  the  axillary  artery  hy  the  Y-shaped  union  of  its  two  heads,  the  external  and 
internal.  The  external  head  arises,  with  the  musculo-cutaneous,  from  the  outer 
coid;  the  internal  head,  with  the  ulnar,  from  the  inner  cord.  The  internal  head 
crosses  iii  front  of  the  third  portion  of  the  axillary  artery. 

The  ulnar  nerve  is  the  continuation  of  the  inner  cord.  It  lies  upon  the  innei 
side  df  the  third  portion  of  the  axillary  artery,  between  it  and  the  axillary  vein, 
and  then  passes  down  the  inner  side  of  the  arm  upon  the  inner  surface  of  the 
trice)  is. 

The  internal  cutaneous  nerve  arises  from  the  inner  cord  and  passes  downward 
on  the  inner  side  of  the  axillary  artery,  between  this  vessel  and  the  ulnar  nerve. 

The  lesser  internal  cutaneous  nerve  (nerve  of  Wrisberg),  the  smallest 
brand)  of  the  plexus,  arises  from  the  inner  cord,  passes  behind  the  axillary  vein 
and  then  along  its  inner  side,  where  it  is  joined  by  the  intercosto-humeral,  which 
is  the  lateral  cutaneous  branch  of  the  second  intercostal  nerve.  The  axillary  vein 
separates  the  lesser  internal  cutaneous  nerve  from  the  ulnar  nerve  and  the  third 
portion  of  the  axillary  artery. 

The  musculo-spiral,  the  largest  branch  of  the  plexus,  is  one  of  the  two  ter- 
minal branches  of  the  posterior  cord,  the  other  terminal  branch  being  the  circum- 
flex nerve.  It  lies  behind  the  third  portion  of  the  axillary  artery  and  in  front  of 
the  subsca  pular  latissimus  dorsi  and  teres  major  muscles. 

The  intercosto-humeral  nerve,  the  lateral  cutaneous  branch  of  the  second 
intercostal  nerve,  passes  outward  across  the  axilla  from  the  inner  wall  to  the  inner 
side  of  the  arm.  It  joins  the  lesser  internal  cutaneous  nerve,  pierces  the  deep 
fascia  (floor  of  the  base  of  the  axilla),  and  terminates  in  filaments  which  are 
distributed  to  the  skin  of  the  inner  and  back  part  of  the  arm.  This  branch 
differs  from  the  other  lateral  cutaneous  branches  of  the  intercostal  nerves  in 
being  larger  and  in  not  dividing  into  an  anterior  and  a  posterior  branch.  It  is 


<->•_>  SURGICAL   AXATOMY. 

not  uncommon  to  meet  \vitli  two  intercosto-humeral  nerves,  in  which  event  the 
second  is  formed  l>y  the  posterior  branch  of  the  lateral  cutaneous  branch  of  the 
third  intercostal.  The  second  iiitcrcosto-huineral  nerve  accompanies  the  first  in 
its  distribution.  All  of  the  lateral  cutaneous  branches  of  the  intercostal  nerves 
emerge  from  the  intercostal  spaces  midway  between  the  vertebra'  and  the  sternum, 
and,  with  the  exception  of  the  second,  divide  into  an  anterior  and  a  posterior 
branch.  The  first  intercostal  nerve  does  not,  as  a  rule,  give  oil'  a  lateral  cutaneous 
branch.  Three  intercosto-humeral  nerves  are  not  infrequently  seen,  the  third  one 
coming  from  the  fourth  intercostal  nerve. 

The  posterior  or  long  thoracic  nerve  (external  respiratory  nerve  of  Bell)  is  a 
branch  of  the  braehial  plexus  given  off  above  the  clavicle,  and  lies  along  the 
inner  wall  of  the  axilla.  It  arises  by  three  roots — the  upper  two  from  the  fifth 
and  sixth,  and  the  lower  from  the  seventh  cervical  nerve.  The  upper  two 
roots  pierce  the  scalenus  rnedius  muscle,  while  the  lower  root  passes  in  front 
of  it.  l/sually,  the  portion  of  the  nerve  formed  by  the  union  of  the  upper 
two  roots  and  that  formed  by  the  knver  root  pass;  into  the  axilla  separately 
behind  the  axillary  plexus  and  vessels,  where  they  join  to  form  the  common 
trunk  which  supplies  the  serratus  magnus.  It  lies  upon  the  outer  surface 
of  that  muscle. 

The  axillary  lymphatic  glands,  ten  to  twelve  in  number,  most  of  which  have 
been  removed  when  clearing  away  the  areolar  and  fatty  tissue  in  exposing  the 
contents  of  the  arm-pit,  consist  of  three  chains — an  anterior,  a  middle,  and  a  pos- 
terior. The  initn-ini-  cJinln  lies  on  the  serratus  magnus,  along  the  lower  border  of 
the  pcctoralis  minor,  and  in  relation  with  the  long  thoracic  vessels.  It  receives 
most  of  the  lymphatics  of  the  mammary  gland,  particularly  those  from  its  outer  por- 
tion, the  lymphatics  of  the  front  of  the  chest,  as  well  as  the  superficial  lymphatics  of 
the  abdominal  wall  as  low  as  the  umbilicus.  The  glands  comprising  this  chain  arc' 
usually  the  first  to  become  enlarged  in  certain  affections  of  the  mammary  gland, 
especially  carcinoma.  The  )/(/</<///•  clmlii.  comprising  the  greater  number  of  glands. 
lies  along  the  inner  side  of  the  axillary  vein  and  extends  into  the  neck,  by  way  of 
the  apex  of  the  arm-pit,  to  become  continuous  with  the  chain  along  the  subclavian 
vessels.  This  chain  receives  most  of  the  lymphatics  of  the  upper  extremity  ami 
the  efferent  vessels  of  the  anterior  and  posterior  chains.  In  cases  of  advanced 
disease  involving  the  glands  of  either  the  anterior  or  the  posterior  chain  the  glands 
of  the  middle  chain  also  become  enlarged,  owing  to  their  receiving  most  of  the 
efferent  vessels  from  both  of  these  chains.  The  posterior  chain  lies  along  the  lower 
margin  of  the  posterior  wall  of  the  axilla,  in  relation  with  the  subscapular  vessels; 
it  receives  the  lymphatics  of  the  back.  To  the  operation  for  the  removal  of 
enlarged  axillary  glands  we  have  already  alluded.  In  this  connection  attention 


PLATE  XXIV, 


Line  of  incision  for  exposure 
of  musculo-spiral  n. 


INCISIONS  FOR  DISSECTION. 
94 


THE   l-'liOXT   or   Till-:  A11M.  !>"> 

may  again  lie  called  to  the  importance  of  tin-  relation  that  the  middle  chain  holds 
to  the  axillary  vein  :  for  when  these  glands  are  diseased,  they  are  apt  in  lie  adherent 
to  this  vessel  and  its  sheath,  under  which  circumstances  the  vein  may  he  wounded 
and  necessitate  excision  of  a  portion  of  the  vessel.  Enlarged  axillary  glands 
may  press  upon  the  axillary  vein  and  thus  produce  edema  of  the  arm.  Kdema 
of  the  arm  following  removal  of  the  glands  and  areolar  tissue  of  the  axilla  may  lie 
due  to  the  loss  of  support  afforded  the  axillary  vein  by  these  structures. 

The  areolar  and  adipose  tissue  which  occupy  the  axilla  are  considerable  in 
amount,  and  fill  up  the  intervals  between  the  other  and  more  important  structure-. 
This  tissue  will  appear  more  red  in  color  and  more  granular  and  watery  in 
character  than  adipose  tissue  elsewhere. 

PissKtTioN. — I'pon  the  opposite  side  of  the  body  the  axilla  should  be  dissected 
from  below  upward.  Remove  the  skin  and  superficial  fascia  in  the  manner  already 
described,  when  will  be  seen  both  the  deep,  or  pectoral,  and  the  axillary  fascia. 

The  axillary  fascia  may  be  removed  in  one  flap  or  divided  longitudinally  and 
reflected  laterally,  the  dissection  being  carried  far  enough  beyond  the  lower  borders 
of  the  folds  of  the  axilla  to  expose  them  thoroughly.  In  removing  the  axillary 
fascia  care  should  be  taken  to  disturb  as  little  as  possible  the  areolar  tissue  of  this 
space,  which  is  closely  connected  to  the  upper  surface  of  the  fascia.  The  areolar 
tissue  is  now  to  be  removed,  exposing,  first,  the  intercosto-humeral  nerve.  The 
other  structures  seen  in  this  dissection  and  along  the  outer  wall  are  the  axillary 
vein  and  artery,  the  middle  chain  of  lymphatic  glands,  and  the  axillary  plexus  of 
nerves;  along  the  posterior  wall,  the  long  subscapular  nerve,  accompanying  the 
subsea pillar  artery  and  vein,  the  middle  and  short  subscapular  nerves,  and  the 
posterior  chain  of  lymphatic  glands  ;  along  the  inner  wall,  the  long  thoracic  nerve  ; 
and  along  the  anterior  wall,  the  long  thoracic  artery  and  vein  and  the  anterior 
chain  of  lymphatic  glands. 

To  open  a  deeply-seated  axillary  abscess  great  care  should  be  exercised.  The 
skin  and  fascia  should  be  incised,  after  which  a  grooved  director  is  pushed  forward 
until  the  outflow  of  pus  along  the  groove  denotes  the  finding  of  the  cavity.  A 
dressing  forceps  is  to  be  introduced  and  forcibly  withdrawn  after  having  been 
partly  opened.  This  is  Hilton's  method,  and  was  suggested  by  him  more 
especially  for  the  opening  of  deep  abscesses  of  the  neck,  so  as  to  avoid  injury 
to  the  important  structures  there  located.  The  more  rational  method  is  to 
open  the  abscess  by  careful  dissection. 


'.ii ;  SURGICAL   .-I .V.I  TOMY. 

THE  FI!(/.\T  or  Till-:  .1/,M/. 

DISSKCTKIX. — Continue  tlie  incision  already  made  upon  the  outer  side  of  the 
arm  to  a  point  on  I  lie  outer  side  of  Ilie  forearm,  about  three  inches  below  tin- 
external  condvle.  From  the  lower  end  of  this  incision  make  another  transversely 
across  tlie  front  of  the  forearm.  Helled  the  skin  inward  as  one  large  flap,  when 
the  superficial  fascia,  with  its  ramifying  nerves  and  vessels,  will  he  exposed. 

The  Superficial  Fascia. — This  fascia  is  composed  of  two  layers — a  superlicial, 
consisting  mainly  of  adipose  tissue;  and  a  deep  layer,  fibrous  in  structure  and  in 
direct  contact  with  the  deep  fascia.  Between  the  two  layers  are  the  superlicial 
nerves,  vessels,  and  lymphatics.  In  the  fascia  upon  the  outer  side  of  the  arm  are 
found  the  cutaneous  branches  of  the  circunillex  nerve  near  the  deltoid  insertion, 
and  helow  these  the  external  cutaneous  branches  of  the  musciilo-spiral  nerve,  while 
immediately  above  the  elbow  the  musculo-cutaneous  nerve  becomes  subcutaneous 
on  the  outer  side  of  the  tendon  of  the  biceps.  Tn  addition  to  these  nerves,  the 
cephalic  vein  is  seen  on  the  outer  side  of  the  arm.  In  the  fascia  on  the  inner 
side  of  the  arm  are  found  the  intercosto-hunicral  nerve,  the  internal  cutaneous 
brancb  of  the  musculo-spiral  nerve,  the  internal  cutaneous  and  lesser  internal 
cutaneous  nerves,  and  the  basilic  vein.  In  order  to  trace  these  nerves  and 
vessels  the  superficial  fascia  is  to  be  removed  as  the  skin  was,  being  careful  not 
to  sever  tlie  structures  which  enter  it  from  beneath.  As  each  nerve  or  vessel 
is  exposed,  trace  it  through  the  superlicial  fascia. 

The  cutaneous  branches  of  the  superior  division  of  the  circumflex  nerve 
pierce  the  deltoid  near  its  insertion  and  are  distributed  to  the  skin  over  the  lower 
part  of  this  muscle  ;  the  end  of  the  inferior  division  of  the  circumflex  nerve  emerges 
from  beneath  the  posterior  edge  of  the  deltoid,  whence  it  ascends  snbcutaneouslv 
to  supply  the  skin  over  the  long  head  of  the  triceps  and  the  lower  two-thirds  of  the 
back  of  the  deltoid. 

The  superior  and  inferior  external  cutaneous  branches  of  the  musculo-spiral 
nerve  emerge  through  the  deep  fascia  at  about  the  middle  of  the  outer  side  of  the 
arm.  Tlie  superior  branch  accompanies  the  cephalic  vein  to  the  front  of  the 
elbow  and  supplies  the  skin  of  the  lower  half  of  the  front  of  the  arm.  The 
inferior  branch  pierces  the  deep  fascia  below  the  deltoid  insertion,  whence  it  passes 
downward  to  supply  the  skin  on  the  outer  side  of  the  lower  half  of  the  arm,  the 
elbow,  and  the  outer  side  of  the  forearm,  communicating  near  the  wrist  with  the 
posterior  branch  of  the  external  or  musculo-cutaneous  nerve. 

The  internal  cutaneous  nerve,  in  company  with  the  basilic  vein,  pierces  the 
deep  fascia  of  the  inner  side  of  the  arm  at  the  junction  of  the  middle  with  the 
lower  one-third,  and  divides  into  an  anterior  and  a  posterior  branch.  It  also  gives 


PLATE  XXV. 


Supra  acromia!  n 


Cutaneous  branch  of  circumflex  n.__ 
Intercosto-humeral  n. 


Branch  of  internal  cutaneous  n. 


Lesser  Internal  cutaneous  n._ 


Internal  cutaneous  n._ 
External  cutaneous  branch  of 

musculo-spiral  n. „ 


Mifsculo-cutaneous  rt._ 


Palmar  cutaneous  branch  of  ulnar  n._ 
Palmar  cotaneous  branch  of  radial  n. 
Palmar  cutaneous  branch  of  median  i 


Digital  n 


Supra  acromial  n. 


Branch  of  circumflex  n. 


Internal  cutaneous  branch  of 
musculo-spiral  n. 

Intercosto-humeral  n. 


Branch  of  circumflex"  n. 


Lesser  internal  cutaneous  n. 


Branch  of  internal  cutaneous  n. 
ternal  cutaneous  of  musculo-spiral  n. 

Branch  of  musculo-cutaneous  n. 


Radial  n. 

Dorsal  cutaneous  branch  of  ulnar  n. 


CUTANEOUS  NERVES  OF  ARM  AND  FOREARM. 
97 


PLATE  XXVI. 


Deep  fascia- 


Branch  of  internal  cutaneous  n.— 
Cephalic  v. 


External  cutaneous  branches  of  musculo-spiral  n 


Radial  v: 

Median  cephalic  v.— 


Deep  median  v. 
Musculo-cutaneous  v  — 


Branch  of  radial  n.- 


SUPERFICIAL  VEINS  OF  FRONT  OF  ARM  AND  FOREARM. 
100 


Basilic  v. 

Internal  cutaneous  n. 

Common  ulnar  v. 

Median  basilic  v. 
Posterior  ulnar  v 

Anterior  ulnar  v. 
Median  v. 


PLATE  XXVII. 


Posterior  ulnar  v. 


Communication  with  deep  veins 


~ 


-Deep  fascia 


.Radial  v. 


SUPERFICIAL  VEINS  OF  BACK  OF  FOREARM  AND  HAND. 
101 


TIIT.    FHOXT   OF   Till':   ,1AM/.  103 

oil'  a  cutaneous  branch  wliicli  arises  high  up,  pierces  llic  deep  fascia  at  the  lower 
border  of  tiie  posterior  fold  of  the  axilla,  ami  goes  to  the  skin  of  the  inner  side 
and  front  of  the  arm.  The  anterior  branch  passes  downward  over  the  elbow, 
cither  in  front  of  or  behind  the  median  basilic  vein,  to  supply  the  skin  of  the 
front  and  inner  side  of  the  forearm.  At  the  wrist  it  communicates  with  a 
cutaneous  branch  of  the  ulnar  nerve.  The  posterior  branch  communicates  with 
the  lesser  internal  cutaneous  nerve  above  the  elbow,  and  then  passes  downward 
behind  the  internal  condyle  to  supply  tin-  skin  over  the  posterior  and  inner 
aspect  of  the  forearm,  and  communicates  with  the  dorsal  branch  of  the  ulnar 
nerve  above  the  wrist-joint. 

The  lesser  internal  cutaneous  nerve  (nerve  of  \Vrisberg)  pierces  the  deep 
fascia  at  the  middle  of  the  arm,  supplies  the  skin  over  the  lower  one-third  of  the 
back  of  the  arm  as  well  as  that  over  the  internal  eondvle  and  olecranon,  and 
communciates  with  the  posterior  branch  of  the  internal  cutaneous  nerve. 

The  internal  cutaneous  branch  of  the  musculo-spirnl  nerve  is  small.  It  arises 
in  the  axilla,  and  pierces  the  deep  fascia  in  the  upper  part  of  the  arm  to  supply 
the  skin  of  the  inner  side  and  back  of  the  arm  almost  as  far  as  the  olecranon. 

Superficial  Arteries. — The  arteries  which  ramify  in  the  superficial  fascia  of 
the  arm  are  derived  from  above  downward — from  the  acromio-thoracic.  the  anterior 
and  posterior  circumflex,  the  superior  and  inferior  profnnda,  the  muscular,  and  the 
aiiastomotica  inagna. 

Superficial  Veins. — The  veins  found  in  the  superficial  fascia  of  the  arm  are 
of  special  interest  because  of  their  symmetric  arrangement  and  surgical  impor- 
tance', those  in  front  of  the  elbow  being  especially  important  in  venesection  or 
blood-letting.  Like  veins  generally,  they  are  subject  to  frequent  variations;  but 
nevertheless  adhere,  as  a  rule,  to  the  following  plan  : 

The  cephalic  vein  is  formed  by  the  junction  of  the  radial  and  median  cephalic 
veins  in  the  groove  between  the  supinator  longus  and  the  lower,  tapering  end  of  the 
biceps  muscle.  It  passes  upward  over  the  outer  edge  of  the  biceps  muscle;  and, 
after  piercing  the  deej)  fascia,  dips  into  the  delto-pectoral  sulcus,  where  it  is  accom- 
panied by  the  descending  branch  of  the  acromio-thoracic  artery.  Just  below  the 
middle  of  the  clavicle  it  pierces  the  costo-coracoid  membrane  and  empties  into  the 
third  portion  of  the  axillary  vein. 

The  median  cephalic  vein  is  a  short,  venous  trunk,  from  one  and  one-half  to 
two  and  one-half  inches  in  length,  connecting  the  lower  end  of  the  cephalic  vein 
with  the  upper  end  of  the  median  vein  of  the  forearm,  from  which  it  arises,  in 
common  with  the  median  basilic,  about  opposite  the  lower  end  of  the  tendon  of 
the  biceps.  It  crosses  the  external  or  muscnlo-cutaneous  nerve. 

The  median  basilic  vein,  generally  shorter  but  of  larger  caliber  than  the 


Hi!  SURGICAL   ANATOMY. 

median  cephalic,  extends  inward  in  front  of  the  bicipital  fascia,  observing  a  more 
nearly  transverse  course  than  tin-  latter  vein.  It  joins  the  common  nlnar  vein  shortly 
after  the  formation  of  the  latter  !>y  the  junction  of  the  anterior  and  posterior  nlnar 
veins.  It  generally  follows  the  course  of  the  sulcus Tsetween  the  inner  edge  of  the 
lower  end  of  the  biceps  and  the  outer  edge  of  the  pronator  radii  teres.  It  cro 
the  hracliial  artery,  from  which  it  is  separated  by  the  bicipital  fascia.  Brandies  <  f 
the  internal  cutaneous  nerve  pass  in  front  of  and  lieliind  it.  This  is  the  vein 
most  commonly  selected  for  intra-venons  saline  infusion. 

In  venesection,  or  blood-letting,  this  is  the  vessel  usually  selected  for  that 
purpose,  hecause  it  is  the  larger  of  the  two.  and  therefore  affords  a  freer  ilo\v  of 
blood.  From  an  anatomic  standpoint,  however,  the  median  cephalic1  is  the  safer 
of  the  two  vessels  from  which  to  bleed,  on  account  of  the  more  intimate  relation  of 
the  median  basilic  vein  to  the  brachial  artery.  When  the  practice  of  bleeding  was 
so  common,  the  thumb  lancet  was  used  in  making  the  set-lion  of  the  vein.  As  the 
blade  of  this  instrument  was  at  a  right  angle  to  the  handle  and  was  driven  by  a 
spring,  it  can  be  readily  understood  why  the  artery  was  endangered  if  the  lancet 
was  not  held  at  the  proper  height.  To  obviate  the  risk  of  injuring  the  brachial 
artery,  the  vein  should  be  exposed  by  dissection  and  cut  obliquely  in  prefeience  to 
transversely  to  preclude  the  danger  of  completely  dividing  the  vessel.  The  open- 
ing in  the  skin  should  be  larger  than  that  in  the  vein,  so  that  blood  will  not 
escape  into  the  cellular  tissue  and  form  a  thrombus.  If  the  blood  does  not  flow 
freely  when  the  vein  is  opened,  the  patient  should  move  his  fingers  while  grasping 
something  in  his  hand  ;  this  favors  compression  of  the  deep  veins  and  causes -the 
blood  to  flow  into  the  superficial  veins  through  the  mediana  profunda  and  the 
remaining  veins  that  connect  the  superficial  and  deep  veins. 

The  basilic  vein,  which  is  much  larger  than  the  cephalic,  is  formed  by  the 
junction  of  the  common  ulnar  and  median  basilic  veins,  and  passes  upward  in 
front  of  the  inner  margin  of  the  biceps  to  pierce  the  deep  fascia  at  the  junction 
of  the  lower  with  the  middle  one-third  of  the  arm.  It  passes  upward  along  the 
inner  side  of  the  brachial  artery  to  become  the  axillary  vein  at  the  lower  border 
of  the  tendon  of  the  teres  major. 

Lymphatics. — Lymphatic  glands  are  generally  found  at  the  elbow,  some- 
times two  or  three  in  front  and  one  or  two  near  the  lower  end  of  the  basilic  vein 
and  internal  eondyle.  Special  interest  centers  in  them  because  they  become 
swollen  and  inflamed  in  poisoned  wounds  of  the  hand. 

The  gland  in  front  of  and  above  the  internal  eondyle,  known  as  the  epitroch- 
lear,  is  often  found  enlarged  in  early  syphilis.  It  is  usually  single,  but  sometimes 
two,  or  even  three,  glands  are  found  in  this  location. 

The  superficial  lymphatics,  beginning  below  the  elbow  and  formed  by  the 


PLATE  XXVIII. 


SUPERFICIAL  LYMPHATIC  VESSELS  AND  GLANDS  OF  FRONT  OF  UPPER  EXTREMITY. 

105 


THE  Fi;<)\T   Oh'    Till-:   Aim.  107 

junction  of  the  lymphatics  from  the  outer  and  inner  side  of  the  front  of  the 
forearm,  pass  along  the  inner  side  of  the  arm  \vith  the  basilic  vein  to  enter  the 
axillary  glands.  A  few  of  those  on  the  outer  side  of  the  forearm  pass  up  the 
outer  side  of  the  arm  with  the  cephalic  vein  and.  crossing  the  biceps  in  its  upper 
part,  join  the  axillary  glands,  though  one  or  two  lymphatic  vessels  usually  con- 
tinue with  the  cephalic  vein  through  the  delto-pectoral  sulens  to  enter  the 
suhclaviau  glands.  The  dee]>  lymphatics  follow  the  course  of  the  arteries.  One  or 
more  lymph-glands  are  occasionally  found  in  the  delto-pectoral  sulcus. 

Reflect  the  superficial  fascia  in  the  same  manner  in  which  the  skin  was 
reflected.  In  removing  this  fascia  the  superficial  veins  and  nerves  are  to  be 
traced.  It  is  more  convenient  to  follow  these  structures  through  the  under  surface 
of  the  fascia. 

Deep  fascia. — The  removal  of  the  superficial  fascia  exposes  the  dee])  fascia, 
which  is  fibrous  in  structure.  It  is  continuous  with  its  adjacent  counterparts  of 
the  shoulder,  back,  chest,  and  forearm.  It  is  attached  above  to  the  anterior  edge 
of  the  clavicle  and  to  the  outer  and  inferior  edges  of  the  acromion  process  and 
spine  of  the  scapula.  Passing  downward,  it  envelops  the  muscles  and  other  deep 
structures  of  the  arm  and  is  attached,  below  the  tendon  of  the  triceps  muscle, 
to  the  bony  prominences  of  the  elbow-joint,  the  olecranon  and  condyles,  whence 
it  continues  downward  as  the  general  investiture  of  the  forearm.  In  addition  to 
enveloping  the  muscles  by  means  of  processes  constituting  sheaths,  it  forms  parti- 
tions between  them.  Two  of  these,  one  on  either  side  of  the  arm,  are  known  as 
the  internal  and  external  intermuscular  septa,  It  varies  in  thickness,  being 
thickest  over  the  triceps  and  the  condyles  of  the  humerus,  thinnest  in  front  of  the 
biceps,  and  intermediate  in  thickness  upon  the  inner  side  of  the  arm,  where  it 
serves  to  cover  and  protect  the  main  vessels  and  nerves.  Internally,  it  is  rein- 
forced by  accessory  fibers  from  the  tendons  of  the  pectoralis  major  and  latissimus 
dorsi,  and  externally  by  fibers  from  the  tendon  of  the  deltoid. 

The  intermuscular  septa. — The  internal  intermuscular  septum  is  attached 
to  the  internal  eondyloid  ridge,  and  extends  from  the  insertion  of  the  coraco- 
hrachialis  to  the  internal  condyle  of  the  humerus.  It  blends  with  the  tendon 
of  the  coraco-brachialis,  and  gives  attachment  to  the  triceps  behind  and  the 
brachialis  anticus  and  pronator  radii  teres  in  front.  In  the  middle  of  the  arm 
it  is  perforated  by  the  ulnar  nerve  and  inferior  profunda  artery,  and  below 
by  the  anastomotica  magna  artery.  The  external  intermuscular  septum  is 
attached  to  the  external  condyloid  ridge,  and  extends  from  the  insertion  of  the 
deltoid  to  the  external  condyle  of  the  humerus.  It  blends  with  the  tendon  of 
the  deltoid  and  gives  attachment  to  the  triceps  behind,  and  to  the  brachialis 
anticus,  supinator  longus,  and  extensor  carpi  radialis  longior  in  front.  It  is  per- 


10S  SURGICAL   ANATOMY. 

forated  below  the  middle  of  the  unn  by  the  musculo-spiral  nerve  and  tlic  superior 
profunda  artery. 

These  intermuscular  septa,  with  tin1  lion.',  divide  the  lower  half  of  the  arm 
into  i\\"  osteo-fascial  compartments — an  anterior  and  a  posterior.  In  the  anterior 
compartment  are  found  the  biceps,  the  brachiahs  anticus,  and  the  origins  of  the 
supinator  longus  and  extensor  carpi  radialis  lougior,  tlie  brachial  vessels,  the 
basilic  vein,  the  anastomotica  magnu,  the  inferior  profunda  and  the  termination 
of  the  superior  profunda,  the  radial  recurrent  and  anterior  ulnar  recurrent 
arteries,  the  median,  ulnar,  internal  cutaneous,  and  musculo-cutaneous  nerves, 
and  the  lower  part  of  the  musculo-spiral  nerve.  In  the  posterior  compartment 
are  the  triceps  muscle,  the  musculo-spiral  nerve,  the  superior  profunda  artery,  the 
ulnar  nerve,  the  inferior  profunda  artery,  and  the  anastomotica  magna  artery. 

DISSECTION. —  Divide  the  deep  fascia  in  the  median  line  of  the  front  of  the 
arm  and  reflect  it  laterally,  exposing  to  view  those  structures  which  lie  in  the  ante- 
rior part  of  the  arm.  In  rellecting  the  fascia  from  the  inner  side  of  the  arm  it  is 
best  to  sever  the  internal  intermuscular  septum,  taking  care,  however,  not  to 
injure  the  structures  that  pierce  it.  This  will  expose,  in  front,  the  biceps;  on 
the  inner  side,  the  coraco-brachialis,  the  brachialis  anticus.  and  the  triceps;  on 
the  outer  side,  the  deltoid,  brachialis  anticus,  and  the  origins  of  the  supinator 
longus  and  extensor  carpi  radialis  longior.  The  sulcus  upon  the  inner  side 
of  tlie  arm,  between  the  biceps  in  front  and  the  triceps  and  brachialis  anticus 
behind,  is  occupied  by  the  principal  vessels  and  nerves.  Before  proceeding  fur- 
ther with  the  dissection  the  student  should  carefully  examine  the  relation  of  the 
brachial  vessels  to  the  coraco-brachialis  and  biceps  muscles,  and  the  median  nerve 
which  accompanies  the  vessels,  as  the  relations  of  these  structures  are  somewhat 
altered  by  cleaning. 

The  brachial  artery,  the  continuation  of  the  axillary,  begins  opposite  the 
lower  border  of  the  tendon  of  the  teres  major.  It  passes  down  the  inner  side  of 
the  arm,  overlapped  for  fully  two-thirds  of  its  course  by  the  inner  border  of  the 
coraco-brachialis  and  biceps  muscles.  It  then  curves  inward  in  front  of  the  elbow- 
joint,  along  the  inner  border  of  the  tendon  of  the  biceps,  opposite  the  insertion 
of  which,  one-half  to  one  inch  below  the  elbow-joint,  it  divides  into  the  radial  and 
ulnar  arteries.  Its  course  is  quite  accurately  indicated  by  a  line  drawn  from  the 
junction  of  the  anterior  and  middle  third  of  the  outer  wall  of  the  axilla,  to  the 
middle  of  the  front  of  the  elbow-joint.  It  should  be  remembered  that  the  hrachial 
artery  quite  frequently  bifurcates  some  distance  above  the  usual  point,  the  two 
vessels  then  running  side  by  side. 

RELATIONS  OF  THE  BKACIIIAL  AKTKRY. — From  above  downward,  upon  its  outer 
side',  are  the  coraco-brachialis  and  the  biceps,  which  slightly  overlap  the  artery. 


PLATE  XXIX. 


Deltoid  m.— 

Cephalic  v. — 

Pectoralls  major  m. 

Coraco-brachialis  m  - 

Short  head  of  biceps  m. — 

Brachia!  a.— 
Long  head  of  biceps  m.— 


Median  n. — 


Basilic  v 


Median  basilic  v 

Supinator  longus  m. 
Bicipital  fascia- 
Biceps  tendon 
Radial  a 


—  Lesser  internal  cutaneous  n 

—  Dinar  n. 
-Teres  major  m. 
Basilic  v. 

Long  head  of  triceps  m. 
Musculo-spiral  n. 
Superior  profunda  a. 
Internal  cutaneous  n. 


Ulnar  n. 

Inferior  profunda  a. 

Lesser  internal  cutaneous  n. 
inner  head  of  triceps  m 


Anastomotica  magna  a. 
Internal  intermuscular  septum 


Posterior  ulnar  v. 
Pronator  radii  teres  m. 
Anterior  ulnar  v. 

Flexor  carpi  radialis  m. 
Palmaris  longus  m 

Flexor  carpi  ulnaris  m 


BRACHIAL  ARTERY  AND  BICEPS  MUSCLE. 
110 


PLATE  XXX. 


Anterior  circumflex  a. 


Posterior  circumflex  a. 


Muscular  branch 


Radial  recurrent  a. 


Posterior  interosseous  recurrent  a. 


Radial  a. 


Axillary  a. 

Subscapular  a, 
Dorsalis  scapulae  a. 


Superior  profunda  a. 
Inferior  profunda  a. 

Brachial  a. 


Nutrient  a. 


Anastomotica  magna  a. 


Anterior  ulnar  recurrent  a. 


Posterior  ulnar  recurrent  a. 


Ulnar  a. 


BRACHIAL  ARTERY  AND  BRANCHES. 
Ill 


THE   /7,'o.V/'   OF    Till-:  ARM.  113 

\Vlini  the  biceps  arises  by  three  heads,  tin.-  artery,  at  its  upper  portion,  lies  beneath 
tin.'  innermost  head.  The  median  nerve,  for  about  one  inch,  also  lies  on  its  outer  side 
in  the  groove  between  the  artery  and  the  coraco-brachialis.  In  front  of  the  artery 
are  the  skin  and  fascia-,  the  inner  borders  of  the  coraco-brachialis  and  biceps  in 
the  upper  two-thirds  of  its  course,  the  median  nerve  in  the  middle  third,  and  the 
bieipital  fascia  and  median  basilic  vein  below;  on  the  inner  side  are  the  ulnar  nerve 
in  tlie  upper  half  of  its  course,  the  internal  cutaneous  nerve  and  basilic  vein  in  the 
upper  two-thirds  of  its  course,  and  the  median  nerve  in  the  lower  third ;  behind 
are  the  musculo-spiral  nerve  and  superior  profunda  artery,  the  long  and  inner 
heads  of  the  triceps  in  the  upper  part  of  the  arm,  the  insertions  of  the  coraco- 
brachialis  in  the  middle,  and  the  braehialis  anticus  in  the  lower  part  of  the  arm. 
Throughout  its  course  it  is  flanked  by  two  closely  adjacent  accompanying  veins 
(vena1  coinites).  connected  with  each  other  by  occasional  transverse  veins. 

The  artery  is  comparatively  superficial  throughout  its  entire  extent,  being 
covered  by  skin  and  superficial  and  deep  fascia,  except  in  the  middle  of  its  course, 
where  the  median  nerve  lies  in  front,  and  at  its  lower  end,  where  the  bieipital 
fascia  and  median  basilic  vein  are  in  front  of  it.  It  is  most  readily  compressed  in 
the  middle  of  the  arm,  where  it  rests  upon  the  insertion  of  the  coraco-brachialis. 
The  pressure  should  be  directed  outward  and  backward.  This  is  the  most  suitable 
point  for  compressing  the  artery  with  the  pad  of  the  tourniquet  in  amputation  of 
the  forearm  or  lower  arm. 

The  branches  of  the  brachial  artery  are  the  superior  and  the  inferior  profunda, 
nutrient,  anastomotica  magna,  muscular,  and  occasionally  vasa  aberrantia. 

The  superior  profunda  artery,  the  largest  branch,  arises  from  the  inner  and 
back  part  of  the  upper  end  of  the  brachial,  and,  turning  backward,  it  enters  the 
musculo-spiral  groove  with  the  musculo-spiral  nerve.  In  the  groove  it  passes 
behind  the  humerus,  between  the  inner  and  outer  heads  of  the  triceps,  to  the 
outer  side  of  the  arm,  pierces  the  external  intermuscular  septum,  and  continues 
downward  between  the  braehialis  anticus  and  supinator  longus  muscles  to  the 
elbow,  where  it  anastomoses  with  the  radial  recurrent.  In  its  course  it  sends 
branches  to  supply  the  deltoid,  coraco-brachialis,  and  triceps  muscles,  and  a 
branch  to  anastomose  with  the  circumflex  arteries.  It  gives  off  a  large  posterior 
</,ii<'nJfir  branch  (really  the  continuation  of  the  artery)  which  passes  straight  down 
the  humerus  from  the  musculo-spiral  groove  to  the  back  of  the  elbow-joint, 
accompanied  by  the  branch  of  the  musculo-spiral  nerve  supplying  the  anconeus 
muscle,  and  anastomoses  with  the  interosseous  recurrent  -and  the  anastomotica 
magna. 

The  inferior  profunda  artery  arises  from  the  brachial  near  the  insertion  of 
the  coraco-brachialis,  is  small,  and  passes  downward  and  inward  on  the  surface 


114  SURGICAL  ,i  .Y.I  7-o.i/r. 

of  tin-  inner  head  of  tin-  triceps.  It  pierces  the  internal  interniuscular  septum 
and  accompanies  the  ulnar  nerve  between  the  internal  condyle  and  olecranon,  wlu-iv 
it  anastomoses  with  the  posterior  ulnar  nrunvnt  ami  the  anastomotica  magna. 
It  also  sends  downward  in  front  of  the  internal  condyle  a  small  branch  which 
anastomoses  with  the-  anterior  nlnar  recurrent  and  the  anastomotica  magna. 
At  times  it  arises  with  the  sup'erior  profunda  by  a  common  trunk. 

The  nutrient  artery  leaves  the  brachial  in  the  middle  of  the  arm,  and.  passing 
downward,  pierces  the  tendon  of  the  eoraco-brachialis  to  enter  the  nutrient  canal 
of  the  Immerns  below  the  insertion  of  that  muscle.  Sometimes  it  arises  from  the 
superior  profunda.  Entering  the  bone  with  it  is  a  filament  of  the  musculo- 
cutaneons  nerve. 

The  anastomotica  magna  artery  is  given  off  a  short  distance  above  the 
elbow,  whence  it  passes  inward  over  the  brachialis  anticus  muscle  and  pierces  the 
internal  intermuscular  septum.  It  then  winds  around  the  humerus  between  the 
triceps  and  the  bone,  and  anastomoses  above  the  olecranon  with  the  posterior 
articular  branch  of  the  superior  profunda  and  the  interosseous  recurrent.  \Yhile 
crossing  the  brachialis  anticus  it  gives  off  an  anastomotic  branch  which  also 
pierces  the  internal  intermuscular  septum  to  join  the  posterior  ulnar  recurrent, 
between  the  olecranon  and  the  internal  condyle.  Ascending  and  descending 
branches  are  also  given  off  to  join  the  inferior  profunda  above,  and  the  anterior 
ulnar  recurrent  in  front  of  the  internal  condyle. 

MiiKcultir  l>i-(iiic/i<-n  arise  from  the  outer  side  of  the  brachial  artery  and  supply 
the  coraco-brachialis,  biceps,  and  brachialis  anticus  muscles. 

Vasa  aberrantia  are  long,  narrow  arteries  which  are  occasionally  found  con- 
necting the  brachial  or  axillary  artery  with  some  of  the  main  arteries  of  the  fore- 
arm, usually  the  radial. 

The  vasa  aberrantia,  together  with  the  liberal  anastomosis  around  the  elbow- 
joint,  are  very  important,  as  they  offer  channels  for  collateral  circulation  of  t he- 
blood  when  its  flow  through  the  radial,  ulnar,  or  lower  part  of  the  brachial  arteries 
is  prevented  by  compression,  ligation,  or  trauma. 

The  Muscles  in  Front  of  the  Arm  are  the  biceps,  the  coraco-brachialis,  and 
the  brachialis  anticus. 

The  biceps  is  the  largest  and  most  prominent  muscle  of  this  group.  It  arises 
by  two  heads — the  long  and  the  short.  The  lour/  law!  arises  by  a  tendon  from  the 
upper  border  of  the  glenoid  cavity  of  the  scapula,  being  continuous  with 
the  glenoid  ligament,  by  means  of  which  it  is  united  with  the  long  head 
of  the  triceps,  which  in  turn  arises  from  the  lower  border  of  the  same  cavity. 
The  tendon  of  the  long  head  passes  through  a  sheath  derived  from  the  synovial 
sac  of  the  shoulder-joint,  in  which  it  arches  over  the  head  of  the  humerus.  It 


PLATE  XXXI. 


Coraco-acromial  ligament 


Deltoid  m.(cut) 


Long  head  of  biceps  m 


Tendon  of  oectoralls  major  m.(cut) 


Brachialis  antlcus  m. 


Musculo-cutaneous  n 
Supinator  longus  m. 


Brachial  a. 


Coracoid  process 


Coraco-brachialis  m. 


—  Musculo-cutaneous  n. 
Short  head  of  biceps  m, 
Median  n. 


Basilic  v. 
Long  head  of  triceps  m. 

Inner  head  of  triceps  m 
Ulnar  n. 

Inferior  profunda  a. 
Brachialis  anticus  m. 

Anastomotica  magna  a 


Bicipital  fascia 


Biceps  tendon 


BICEPS  MUSCLE. 
115 


PLATE  XXXII, 


Coraco-acromial  ligament 


Deltuid  m 


Long  head  of  biceps  m. 


Pectoralis  major  tendon 


Brachialis  anticus  m 


Supinator  longus  m 


Biceps  tendon  — 


Pectoralis  minor  tendon 

Short  head  of  biceps  m. 
Anterior  circumflex  a. 

Coraco-brachialis  m. 
Brachial  a. 


Musculo-cutaneous  n. 

Basilic  v. 

.Long  head  of  triceps  m. 


Ulnar  n. 


Inferior  profunda  a. 


Inner  head  of  triceps  m. 


Anastomotica  magna  a. 

Median  n. 


Pronator  radii  teres  m. 

Flexor  carpi  radialis  m. 
Flexor  carpi  ulnaris  m. 


VIEW  OF  ARM, -BICEPS  REMOVED. 
118 


THE   FI,'0.\T   OF   THE  AHM.  II!) 

emerges  from  the  capsule,  where  the  latt.T  unites  with  the  hunicrus.  It  passes 
down  the  bicipital  groove,  in  wliich  it  is  retained  by  an  aponeurosis  derived  t'nun 
tlie  tendon  of  the  pectoralis  major.  Its  synovial  slieatli  covers  it  in  the  upper  two 
inches  of  the  groove.  This  liead  becomes  muscular  shortly  after  leaving  the 
groove.  The  xln.n-t  lu-u<l  takes  its  origin  from  the  ti]>  of  the  coraenid  process  of  the 
scapula  hy  a  flattened  tendon  in  common  with  the  coraco-hrachialis,  whence  it 
passes  downward  and  a  little  outward  to  join  the  long  head  opposite  the  middle  of 
the  humerus.  The  biceps  ends  below  in  a  flattened  tendon,  which,  after  giving  oft' 
an  aponeurotie  expansion  (bicipital  aponeiirosis)  from  its  inner  side,  becomes 
twisted  upon  itself,  and  is  inserted  into  the  posterior  edge  of  the  tuberosity  of  the 
radius.  A  synovial  sac  intervenes  between  (he  tendon  and  the  anterior  part  of  the 
tuberosity.  The  bicipital  aponeurosis  passes  inward  over  the  braehial  artery  and 
beneath  the  median  basilic  vein  and  blends  with  the  deep  fascia  of  the  forearm. 
Interest  attaches  to  the  relation  of  the  braehial  artery  to  the  bicipital  aponeurosis 
and  the  median  basilic  vein,  because,  inexplicable  as  such  an  accident  may  seem. 
it  has  happened  that  the  artery,  as  we'll  as  the  vein,  has  been  opened  in  venesection, 
an  arterio-venous  aneurysm  resulting.  The  two  bellies  of  this  muscle  are  united  by 
connective  tissue  almost  as  far  as  the  tendon,  near  which  their  fibers  interdigitate 
before  attachment  to  the  front  of  this  structure.  The  biceps,  in  its  upper  part,  rests 
upon  the  imisculo-cutaneous  nerve,  which  passes  obliquely  behind  it,  and  against 
the  humerus ;  in  its  lower  half  it  lies  upon  the  brachialis  anticus.  Its  tendon 
occupies  the  triangular  space  in  front  of  the  elbow,  the  braehial  artery  being  on 
its  inner  side.  On  the  inner  side  of  the  muscle  are  the  coraco-brachialis  muscle, 
the  braehial  vessels,  and  the  median  nerve.  Its  upper  end  is  covered  by  the 
tendon  of  the  pectoralis  major  and  the  anterior  edge  of  the  deltoid.  For  the 
remainder  of  its  course  it  is  subcutaneous  and  readily  discernible. 

Occasionally,  between  the  coraco-brachialis  and  brachialis  anticus,  there 
arises  from  the  inner  side  of  the  humerus  an  accessory  head,  which,  in  its 
course  toward  the  bicipital  fascia  for  insertion,  assumes  varying  relations  with 
the  braehial  artery,  either  crossing  in  front  of  or  behind  the  artery,  or  dividing 
to  permit  this  vessel  to  pass  through  it.  In  ligating  the  braehial  artery  an 
accessory  muscular  head,  when  present,  may  be  severed  without  hesitation. 

ACTION. — Its  function  is  to  flex  the  forearm  on  the  arm,  to  supinate  the 
forearm,  and  to  slightly  adduct  the  arm.  It  is  also  well  to  bear  in  mind  that 
in  no  part  of  its  course  is  the  biceps  muscle  normally  attached  to  any  part  of 
the  humerus,  though  bearing  the  most  intimate  relation  to  this  bone  anatomically 
and  functionally. 

BLOOD  SUPPLY. — From  the  muscular  branches  of  the  braehial  artery. 
NERVE  SUPPLY. — From  the  musculo-cutaneous  nerve. 


l^o  SURGICAL    ANATOMY. 

The  coraco-brachialis  muscle,  arising  conjointly  with  the  short  head  of  the 
biceps,  extends  t'roin  tlie  tip  of  the  eomeoid  process  to  the  middle  of  the  inner  side 
of  the  humerus,  where  it  is  inserted  into  a  rough  impression  between  the  attach- 
ment of  the  inner  head  of  the  triceps  and  the  brachialis  anticus.  and  opposite  the 
insertion  of  the  deltoid.  It  is  perforated  obliquely,  from  within  outward,  by  the 
musculo-cutaneoua  nerve,  from  which  it  derives  jt^  nerve  supply.  Aboyi  ,  it  is 
hidden  by  the  pectoralis  major  and  deltoid;  it  then  becomes,  superficial  as  far  as 
its  insertion,  where  it  is  crossed  by  the  bradiial  vessels  and  median  nerve. 
Behind,  this  muscle  is  in  contact  with  the  tendons  of  the  snbscapnlaris.  teres  major, 
and  latissimns  dorsi,  and  the  short  head  of  the  triceps  muscle,  the  humerus,  and 
the  anterior  circumflex  vessels.  Internally,  it  is  in  relation  with  the  pectoralis 
minor,  the  third  part  of  the  axillary  artery,  the  brachial  vessels,  and  the  median 
and  musculo-cntaneous  nerves.  Externally,  it  lies  in  contact  with  the  short  head 
of  the  biceps.  It  derives  its  nutriment  chiefly  from  the  .brachial  artery. 

ACTION*. — Its  function  is  to  draw  the  arm  forward  and  inward. 

The  brachialis  anticus  muscle  arises  from  the  humerus  by  two  fleshy  digita- 
tions  on  either  side  of  the  in-crtion  of  the  deltoid,  and  from  the  front  and  inner 
side  of  the;  shaft  of  the  bone  below  this  point,  as  well  as  from  the  external  and 
internal  intcrnmscnlar  septa.  It  is  a  broad,  flat  muscle,  which  covers  the  lower 
half  of  the  front  of  the  humerus  and  the  anterior  ligament  of  the  elbow-joint,  to 
which  it  is  closely  attached.  It  ends  in  a  short  tendon,  which  is  inserted  into  the 
front  of  the  base  of  the  coronoid  process  of  the  ulna,  where  it  bears  the  same 
relation  to  the  two  (limitations  of  the  flexor  profnndns  digitorum  that  the  inser- 
tion of  the  deltoid  does  to  it  above.  This  muscle  is  covered  by  the  deep  fascia 
on  the  outer  side  and  by  the  biceps,  and  is  crossed  by  the  brachial  vessels,  the 
median,  the  musculo-cutaneous,  and  mnscnlo-spiral  nerves.  Externally,  it  is 
related  with  the  musculo-spiral  nerve,  the  superior  proi'nnda  and  radial  recurrent 
arteries,  the  long  radio-carpal  extensor  and  long  snpinator  muscles;  while 
internally  it  is  in  contact  with  the  triceps,  ulnar  nerve,  and  pronator  radii  teres. 

BLOOD  SUPPLY. — From  the  brachial  artery. 

NERVE  SUPPLY. — From  the  musculo-cutaneous  and  the  musculo-spiral  nerves. 

ACTION. — To  flex  the  forearm  on  the  arm. 

The  Nerves  of  the  Arm  proceed  from  the  axillary  or  brachial  plexus.  They 
are  the  musculo-cutaneous,  from  the  outer  cord  ;  the  median,  from  the  inner  and 
outer  cords ;  the  ulnar,  internal  cutaneous,  and  lesser  internal  cutaneous,  from  the 
inner  cord;  and  the  circumflex  and  musculo-spiral,  from  the  posterior  cord.  The 
ramifications  of  these  in  the  superficial  fascia  have  been  fully  described,  while  the 
course  of  the  main  trunks  has  been  casually  mentioned:  Of  the  larger  nerves, 
the  median  and  ulnar  pass  down  the  inner  side  of  the  arm  ;  the  circumflex  and 


PLATE  XXXIII. 


LINES  OF  ARTERIES  OF  UPPER  EXTREMITY  AND  OF  MEDIAN  AND  ULNAR  NERVES. 

122 


THE  FRONT  OF  THE  ARM.  123 

musculo-spiral  curve  behind  tlie  humerus  to  the  outer  side  of  the  arm  ;  the  nmsculo- 
cutancous  crosses  the  front  of  the  arm  to  the  outer  side  of  the  forearm.  Of  these, 
the  circumflex  is  the  only  one  which  has  ascending  brandies. 

The  musculo-cutaneous  nerve,  arising  from  the  outer  cord  of  the  axillary  or 
brachial  plexus,  opposite  the  lower  margin  of  the  pectomlis  minor,  at  once  enters 
the  coraco-brachial  muscle,  through  which  it,  passes  downward  and  outward,  thence 
between  the  biceps  and  brachialis  anticus  to  the  outer  side  of  the  arm  a  little  above 
the  elbow,  where  it  pierces  the  deep  fascia.  It  supplies  the  coraeo-braehialis, 
biceps,  and  brachialis  anticus  muscles,  the  humeras,  and  the  elbow-joint.  At  the 
elbow  it  passes  beneath  the  median  cephalic  vein  and  divides  into  an  anterior  and 
a  posterior  branch.  The  anterior  branch  communicates  with  the  radial  nerve 
and  ends  in  the  skin  over  the  thenar  eminence  ;  the  posterior  branch  supplies  the 
skin  as  far  as  the  wrist.  Loss  of  the  power  of  elbow  flexion,  associated  with  numb- 
ness or  anesthesia  of  the  outer  side  of  the  forearm,  would  indicate  an  affection  of 
this  nerve. 

The  median  nerve  is  formed  by  two  fasciculi,  or  nerve  strands,  one  from  the 
outer  and  the  other  from  the  inner  cord  of  the  axillary  plexus ;  they  unite  like 
the  arms  of  the  letter  Y  and  are  known  as  the  outer  and  the  inner  heads,  the  stem 
formed  by  their  union  being  the  median  nerve.  The  two  heads  lie  on  opposite 
sides  of  the  lower  or  third  portion  of  the  axillary  artery  and  unite  either  in  front  of 
it  or  on  its  outer  side.  In  its  course  along  the  inner  side  of  the  arm  it  hugs  the 
brachial  artery,  being  generally  upon  the  outer  side  of  this  vessel  in  its  upper  part, 
then  gradually  moving  inward  to  rest  in  front  of  it  in  the  middle  of  the  arm,  and 
continuing  inward  so  that  it  lies  upon  the  inner  side  of  this  vessel  in  the  lower 
third  of  the  arm.  At  the  lower  end  of  the  arm  it  is  covered  by  the  bicipital 
aponeurosis  or  fascia,  and  is  crossed  by  the  median  basilic  vein.  It  gives  off  mus- 
cular branches  and  the  anterior  interosseous  nerve,  and  continues  downward  to  the 
palm.  In  the  middle  of  the  arm  the  median  nerve  is  occasionally  found  behind 
the  brachial  artery,  instead  of  in  front. 

The  ulnar  nerve  arises,  in  common  with  the  inner  head  of  the  median  nerve, 
from  the  inner  cord  of  the  axillary  plexus.  It  passes  downward  along  the  inner 
side  of  the  axillary  and  brachial  arteries,  diverging  inward  from  the  latter  at  the 
middle  of  the  arm  opposite  the  insertion  of  the  coraco-brachialis  muscle.  It  then 
crosses  the  inner  head  of  the  triceps  and,  in  company  with  the  inferior  profunda 
artery,  pierces  the  internal  intermuscular  septum  to  enter  the  groove  between  the 
olecranon  and  internal  condyle.  Special  interest  attaches  to  the  position  of  the 
ulnar  nerve  in  the  sulcus  between  the  internal  condyle  and  the  olecranon,  on 
account  of  its  liability  to  injury  there.  Trauma  of  the  nerve  in  this  position  is 
frequent.  It  is  followed  by  a  tingling  sensation,  felt  at  its  distribution  to  the  little 


1-24  SURGICAL    AXATOMY. 

and  ring  fingers,  whence  is  derived  the  name  "cra/y  bone"  or  "  funny  bone." 
The  ulnar  nerve  holds  so  close  a  relation  to  the  posterior  surface  of  the  internal 
condyle  that,  in  trad  lire  of  the  condyle,  a  fragment  or  callus  may  press  upon  the 
nerve  and  produce  tingling  or  numbness  of  the  ulnar  side  of  the  forearm  and 
hand,  little  finger,  and  ulnar  side  of  the  ring  linger,  and  spasm  or  paralysis  of 
the  muscles  supplied  by  this  nerve.  These  muscles  are  the  flexor  carpi  ulnaris, 
ulnar  side  of  the  flexor  profundus  digitorum,  palmaris  brevis,  muscles  of  the 
hypothenar  eminence,  interossei,  two  ulnar  lumbricales,  adductor  pollicis,  and 
inner  head  of  the  flexor  brevis  pollicis. 

The  internal  cutaneous  nerve  arises  from  the  inner  cord  of  the  axillary 
plexus,  passes  down  ward  along  the  inner  side  of  the  axillary  and  brachial  arteries, 
between  the  latter  and  the  ulnar  nerve,  and  divides  a  little  below  the  middle  of 
the  arm  into  an  anterior  and  a  posterior  branch.  The  anterior  branch  enters  the 
forearm  either  in  front  of,  or  behind,  the  median  basilic  vein  ;  the  posterior  branch 
descends  along  the  inner  side  of  the  basilic  vein  to  enter  the  forearm  behind  the 
internal  condyle.  Before  it  divides,  it  gives  off  a  cutaneous  branch,  which  pierces 
the  deep  fascia  and  supplies  the  skin  of  the  anterior  and  inner  side  of  the  arm 
almost  as  far  as  the  elbow. 

The  lesser  internal  cutaneous  nerve  (nerve  of  Wrisberg)  arises  from  the  inner 
cord  of  the  axillary  plexus  above  the  origin  of  the  internal  cutaneous  nerve,  from 
which  point  it  passes  behind  the  axillary  vein,  and  then  on  the  inner  side  of  the 
vein,  where  it  communicates  with  the  lateral  cutaneous  branch  of  the  second  inter- 
costal nerve  (the  intcrcosto-humeral).  It  then  passes  downward  to  the  middle  of 
the  arm,  where  it  pierces  the  deep  fascia,  and  is  distributed  to  the  skin  over  the 
lower  part  of  the  back  of  the  arm,  the  inner  condyle,  and  the  olecranon. 

The  circumflex  nerve  arises,  with  the  musculo-spiral,  from  the  posterior  cord 
of  the  axillary  plexus.  It  descends  in  front  of  the  subscapularis  muscle  behind 
the  axillary  artery,  and  turns  backward  at  the  lower  margin  of  the  muscle,  giving 
off  an  articular  branch  which  enters  the  shoulder-joint  below  the  subscapularis.  It 
divides  into  an  upper  and  a  lower  branch.  The  upper  branch,  in  company  with 
the  posterior  circumflex  vessels,  curves  behind  the  surgical  neck  of  the  hunicrus 
and  under  the  deltoid  to  its  anterior  border,  giving  off  filaments  in  its  course  to 
supply  the  muscle  and  the  skin  covering  it.  The  lower  branch  sends  to  the  teres 
minor  muscle  a  filament,  usually  containing  a  gangliform  enlargement,  and  one 
or  more  branches  to  the  back  part  of  the  deltoid  ;  it  then  pierces  the  deep  fascia  to 
supply  the  skin  over  the  long  head  of  the  triceps  and  the  lower  two-thirds  of  the 
back  part  of  the  deltoid.  Injury  to  this  nerve  would  cause  tingling  or  partial 
anesthesia,  and  muscular  twitching  or  paralysis  of  the  deltoid  and  teres  minor. 

The   musculo-spiral   nerve   is   the   continuation  of  the  posterior  cord,  and 


•/'///•:  /•7,'o.vv  a i-'  '!'!/!•:  /-'o ///•;.  i /.M/.  .i^r, 

is  tlif  largot  1. ranch  of  the  axillary  plexus.  It  passes  downward  behind  tin- 
axillary  vessels  and  in  front  of  Ilie  tendons  of  tiie  lalissiiuus  dorsi  and  tcres 
niiijur.  Accompanied  by  the  superior  profunda  artery,  it  then  pa>ses  down- 
ward and  outward  between  the  outer  and  inner  heads  of  the  triceps  around  the 
back  of  the  humerus  in  the  nmsculo-spiral  groove  to  the  outer  side  of  the  lower 
part  of  the  arm,  where  ii  pierces  the  external  interniuscular  septum.  Thence  it 
continues  downward  between  the  brachialis  anticus,  internally,  and  the  supinator 
longus,  externally,  to  the  front  of  the  outer  coiulyle,  where  it  divides  into  the 
radial  and  posterior  interosseous  nerves.  On  the  inner  side  of  the  arm  it  gives  off 
lull  rmil  •niiixriiliii'  In'iiiii'licx  to  the  outer  and  inner  heads  of  the  triceps;  in  the 
miisculo-spiral  groove  it  sends  branches  to  the  outer  head  of  the  triceps  and  the 
ancmieus;  on  the  outer  side  of  the  arm  it  gives  off  external  branches  to  the 
snpinator  longus,  extensor  carpi  radialis  longior,  and  brachialis  anticus.  A  small 
inti  1-inil  cutaneous  In-mirli  arises  in  the  axilla,  and  passes  to  the  skin  of  the  inner 
side  and  back  of  the  arm  almost  as  far  as  the  olecranon.  A  superior  external  cuta- 
neous  In-iiiK'li  perforates  the  external  head  of  the  triceps  close  to  the  humerus,  then 
pierces  the  deep  fascia  and  accompanies  the  cephalic  vein  to  the  front  of  the  elbow, 
supplying  the  skin  of  the  lower  half  of  the  front  of  the  arm.  An  inferior  c.iicnial 
cutaneous  I>nnn-Ii  also  goes  through  the  outer  head  of  the  triceps  with  the  preceding 
branch,  then  pierces  the  deep  fascia  near  the  insertion  of  the  deltoid,  and  pa--e- 
downward  to  be  distributed  to  the  skin  on  the  outer  side  of  the  lower  half  of  the 
arm,  the  elbow,  and  the  outer  back  part  of  the  forearm,  communicating  near  its 
termination  with  the  posterior  branch  of  the  musculo-cutaneous  or  external  cuta- 
neous nerve. 

As  the  musculo-spiral  nerve  lies  in  contact  with  the  back  of  the  shaft  of  the 
humerus,  paralysis  of  this  nerve  is  a  complication  of  fracture  of  that  bone. 
Paralysis  of  this  nerve  either  from  fracture  of  the  humerus,  pressure  of  a  crutch, 
lead  poisoning,  or  over-stretching  of  the  nerve,  as  from  lifting  a  child  by  the 
arm,  results  in  "  wrist  drop  "  and  pronation  of  the  forearm. 


THE  FRONT  OF  THE  FOREARM. 

DISSECTION. — Extend  the  forearm  and  hand  so  as  to  make  tense  the  structures 
in  this  region.  Continue  the  incision  made  along  the  outer  side  of  the  arm  down 
the  radial  side  of  the  forearm  to  the  tip  of  the  styloid  process  of  the  radius.  From 
the  latter  point  carry  a  transverse  incision  across  the  front  of  the  wrist.  Reflect 
the  skin  from  without  inward,  when  the  superficial  fascia  and  the  superficial  veins 


AXATOMY. 

will  l>e  exposed.  The  skin  is  thin,  can  lie  raised  in  folds,  and  allows  the  super- 
ficial veins  to  lie  seen  lii'iieath  it. 

In  the  superficial  fascia  are  found  the  radial,  anterior  ulnar,  and  median 
veins,  and  the  niusculo-eutaneous  or  external  cutaneous  nerve,  the  internal  cuta- 
neous nerve,  cutaneous  brandies  of  the  ulnar  and  median  nerves,  branches  of  the 
radial  and  ulnar  arteries,  and  the  superficial  lymphatics. 

The  radial  vein  appears  upon  the  front  of  the  radial  side  of  the  forearm 
above  its  lower  third,  where  it  winds  from  behind  forward  and  upward  on  the 
radial  side  of  the  forearm  (generally  superficial  to  the  external  cutaneous  nerve)  to 
form  the  cephalic  vein  at  the  elbow  by  junction  with  the  median  cephalic.  It 
arises  from  the  radial  side  of  the  dorsal  venous  arch  of  the  hand,  receives  radicles 
from  the  back  of  the  thumb  and  index  finger,  and  communicates  with  the  median 
vein. 

The  anterior  ulnar  vein  passes  upward  along  the  ulnar  side  of  the  forearm  to 
within  a  short  distance  of  the  elbow,  where  it  joins  the  posterior  ulnar  to  form  the 
common  ulnar,  which  in  turn  almost  immediately  unites  with  the  median  basilic 
to  form  the  basilic  vein.  It  is  formed  by  radicles  at  the  wrist,  and  communicates 
with  the  median  and  posterior  ulnar  veins. 

The  median  vein  begins  at,  or  a  little  above,  the  wrist  and  runs  up  the  middle 
of  the  forearm.  It  collects  blood  from  the  palm  of  the  hand  and  the  front  of  the 
forearm,  and  communicates  freely  with  the  radial  and  anterior  ulnar  veins.  Upon 
reaching  the  bend  of  the  elbow,  it  communicates  with  the  vena?  comites  of  the 
radial  artery  by  means  of  the  deep  median  vein  and  at  once  divides  into  two 
branches — the  median  cephalic  and  median  basilic. 

The  musculo-cutaneous  or  external  cutaneous  nerve  becomes  superficial  a 
short  distance  above  the  elbow  on  the  outer  side  of  the  tendon  of  the  biceps,  and 
passes  downward  upon  the  outer  side  of  the  front  of  the  forearm,  ending  upon  the 
ball  of  the  thumb  (thenar  eminence).  It  gives  off,  just  below  the  elbow,  a  posterior 
branch  which  supplies  the  outer  side  of  the  back  of  the  forearm.  The  anterior 
branch — the  continuation  of  the  musculo-cutaneous — lies  in  front  of  the  radial 
artery  in  the  lower  part  of  the  forearm  and  communicates  with  a  branch  of  the 
radial  nerve.  It  terminates  in  filaments  to  the  skin  over  the  ball  of  the  thumb. 

The  anterior  branch  of  the  internal  cutaneous  nerve  enters  the  forearm  at 
the  inner  side  of  the  front  of  the  elbow,  either  in  front  of,  or  behind,  the  median 
basilic  vein  ;  thence  it  continues  downward  upon  the  ulnar  side  of  the  front  of  the 
forearm,  supplying  the  skin  on  its  way  to  the  wrist,  where  it  communicates  with 
a  branch  of  the  ulnar  nerve. 

A  cutaneous  branch  of  the  ulnar  nerve  is  found  coming  through  the  deep  fas- 
cia about  a  hand's  breadth  above  the  wrist  near  the  tendon  of  the  flexor  carpi  ulnaris. 


PLATE  XXXIV. 


Biceps  m.- 


Cephalic  v.- 


Supinator  longus  m. 


Radial  v.- 


Median  cephalic  v. 

Extensor  carpi  radialis  longio 


Musculo-cutaneous  n.- 
Biceps  tendon 


Vena  comites  of  radial  a: 

Deep  median  v. 

Radial  a. 


Median  v.— 


Ulnar  n. 
Inferior  profunds  a. 

Inner  head  of  triceps  m. 
Basilic  v. 
Anastomotica  magna  a. 

Brachiaiis  anticus  m. 
Median  n. 

Brachial  a. 

Internal  cutaneous  n. 

Posterior  ulnar  v. 
Anterior  ulnar  v. 
Pronator  radii  te^es  m. 
Median  basilic  v. 


Bicipital  fascia 


Palmaris  longus  m. 


Flexor  carpi  ulnaris  m. 
Pronator  radii  teres  m. 


BICIPITAL  FASCIA  AND  VESSELS  AND  NERVES  AT  ELBOW. 
128 


THE  FROA'T  OF  THE  FOREARM.  129 

A  cutaneous  branch  of  the  median  nerve  pierces  the  deep  fascia  about  two 
inches  above  the  middle  of  the  wrist  and  pusses  to  the  palm. 

The  superficial  arteries  of  the  forearm  are  small  cutaneous  branches  from 
the  radial  and  ulnar  arteries. 

The  superficial  lymphatics  accompany  the  superficial  veins,  and  are  more 
numerous  upon  the  ulnar  than  upon  the  radial  side  of  the  forearm.  They  com- 
mence at  the  ends  of  the  fingers — two  on  the  palmar  and  two  on  the  dorsal  surface. 
Those  on  the  palmar  surface  of  the  fingers  join  an  arch  in  the  palm  of  the  hand, 
from  which  arise  the  vessels  which  accompany  the  anterior  ulnar,  the  median,  and 
radial  veins  ;  those  on  the  dorsal  aspect  of  the  fingers  form  a  plexus  on  the  back 
of  the  hand,  from  which  vessels  pass  up  the  back  of  the  forearm  and  around  either 
side  to  empty  into  those  on  the  anterior  surface  of  the  forearm.  The  greater 
number  of  these  vessels  pass  upward  on  the  inner  side  of  the  arm  with  the  basilic 
vein.  A  few  accompany  the  cephalic  vein. 

DISSECTION. — Trace  the  superficial  veins  in  the  superficial  layer  of  the  super- 
ficial fascia  and  remove  this  fascia  in  one  flap  like  that  of  the  skin.  Follow  the 
nerves  through  the  under  surface  of  the  fascia.  The  deep  fascia  is  now  exposed. 

The  deep  fascia  of  the  forearm  is  continuous  with  that  of  the  arm,  and  com- 
posed of  circular  and  oblique  white  fibers  bound  together  by  a  few  longitudinal 
fibers.  It  is  attached  to  the  bony  prominences  of  the  forearm,  and  sends  prolonga- 
tions between  the  muscles,  separating  them  and  affording  additional  surfaces  for 
their  origin.  It  is  most  dense  at  the  back  of  the  forearm,  least  so  in  front  of 
the  upper  part  of  the  forearm,  and  intermediate  in  thickness  above  and  at  the 
wrist.  In  the  last-named  location  it  forms  the  posterior  annular  ligament  and 
is  continuous  with  the  anterior  annular  ligament.  It  is  reinforced  by  tendinous 
accessions  from  the  biceps  (bicipital  aponeurosis),  brachialis  anticus,  and  triceps. 
Its  numerous  intermuscular  septa  at  the  elbow,  beginning  at  the  limited  area  of 
the  surface  of  the  internal  condyle  and  expanding,  form  cone-shaped  aponeurotic 
cavities  for  the  origins  of  many  muscles.  A  transverse  intermuscular  septum 
divides  the  muscles  of  the  forearm  into  a  superficial  and  a  deep  group. 
Besides  smaller  apertures  for  the  passage  of  cutaneous  vessels  and  nerves, 
it  contains  an  aperture  of  considerable  size  below  the  elbow  for  the  passage  of 
the  deep  median  vein,  which  connects  the  vense  comites  of  the  radial  artery 
with  the  superficial  veins. 

DISSECTION. — Remove  the  deep  fascia  by  incisions  corresponding  to  those 
used  in  reflecting  the  skin  and  superficial  fascia.  The  removal  of  the  deep  fascia 
at  the  upper  and  inner  part  of  the  forearm  can  not  be  accomplished  so  satisfactorily 
as  in  most  other  regions,  owing  to  its  blending  with  the .  underlying  superficial 
group  of  flexor  muscles,  to  which  it  gives  partial  origin.  It  can  be  removed  to 


!:-!<>  SURGICAL    AXATo.MV. 

better  advantage  by  reflecting  it  from  below  upward.  A  similai1  dilliculty  is 
encountered  at  the  buttock  in  the  removal  of  the  dee]>  fascia  from  the  great  gluteal 
muscle,  the  main  difference  between  the  two  fascia:  being  that,  in  the  gluteal 
region  the  deep  fascia  sends  septa  into  the  muscle  itself,  while  in  the  forearm 
the  septa  pass  between  the  muscles. 

The  triangle  at  the  bend  of  the  elbow. — Upon  the  removal  of  the  deep 
fascia,  a  triangle  is  exposed  ;it  the  bend  of  the  elhnw.  This  triangle  is  hounded 
above1  by  an  imaginary  line  which  is  drawn  between  the  condyles  of  the  Immerus 
and  forms  the  base  :  externally,  by  the  snpinator  longus  :  and  internally,  by  the 
pronator  radii  teres.  The  apex  of  the  triangle  is  at  the  point  where  the  supinator 
longus  crosses  the  pronator  radii  teres.  The  floor  is  formed  by  the  braehialis 
anticus  and  supinator  brevis  muscles,  and  the  deep  fascia  forms  its  roof.  Within 
this  triangle,  when  its  lateral  boundaries  are  displaced, — the  supinator  longus 
outward  and  pronator  radii  teres  inward, — the  following  structures  are  seen  from 
within  outward  :  The  anterior  ulnar  recurrent  artery,  the  median  nerve,  the 
brachial  artery,  its  vena1  comites,  the  two  terminal  branches  of  the  brachial  or 
the  radial  and  ulnar  arteries,  their  vena1  comites,  the  deep  median  vein,  Un- 
common interosseous  artery,  the  tendon  of  the  biceps,  the  radial  recurrent  artery, 
and  the  musculo-spiral  nerve.  In  rupture  of  the  biceps  muscle  the  tendon  can 
be  distinctly  felt  loose  and  free  and  can  be  manipulated  in  tin's  space.  The  effusion 
of  blood  renders  approximation  impracticable  without  operative  interference. 

The  Muscles  of  the  forearm  may  be  divided  into  groups  :  an  inner  or  anterior, 
and  an  outer  or  posterior;  the  former  including  the  pronators  and  flexors  ;  the 
latter,  the  supinators  and  extensors.  The  inner  group  chiefly  arises  by  a  common 
tendon  from  the  internal  condyle  and  internal  condyloid  ridge,  and  the  outer, 
from  the  external  condyle  and  the  external  condyloid  ridge. 

The  pronator  radii  teres,  the  shortest  muscle  of  this  group,  arises  by  two 
heads — a  large  or  superficial,  and  a  small  or  deep.  The  large  or  superficial  head 
springs  from  the  anterior  surface  of  the  humerus  above  the  internal  condyle,  an 
intermuscular  septum  separating  it  from  the  flexor  carpi  radialis  and  the  deep 
fascia  of  the  forearm;  the  small  or  deep  head  arises  as  a  narrow  bundle  of  fibers 
from  the  inner  aspect  of  the  coronoid  process  of  the  ulna.  The  two  heads  unite  at 
an  acute  angle,  and  between  them  passes  the  median  nerve  to  the  deeper  part  of 
the  forearm.  The  muscle  then  extends  obliquely  downward  and  outward,  and  is 
attached  by  a  flat  tendon  to  the  middle  of  the  outer  surface  of  the  shaft  of  the 
radius.  The  tendon  is  overlapped  by  the  supinator  longus.  The  muscle  is  sub- 
cutaneous, except  near  and  at  its  insertion,  where  it  is  covered  by  the  supinator 
longus  and  crossed  by  the  radial  vessels  and  nerve.  The  radial  border  of  the 
muscle  forms  the  inner  boundary  of  the  triangle  at  the  bend  of  the  elbow,  while 


PLATE  XXXV, 


Musculo-cutaneous  n._ 
Biceps  tendon 


Radial  recurrent  a. 
Radial  a 


Supinator  longus  m. 


Extensor  carpi  radialis  longior  m 


Radial  a 


Radial  n. 


Extensor  ossis  metacarpi  pollicis  tendon 
Extensor  primi  intern  odii  pollicis  tendon 


Superficialis  volae  a. 


Branch  of  anastomotica  magna  a. 
Median  n. 


Brachialis  anticus  m. 
Brachial  a. 

Bicipital  fascia 


Pronator  radii  teres  m. 


Ulnar  a. 


Flexor  carpi  ulnaris  m. 


Palmaris  longus  m. 


Flexor  carpi  radialis  m. 


Flexor  sublimis  digitorum  m. 

Median  n. 
Ulnar  a. 

Ulnar  n. 


TRIANGLE  OF  ELBOW  AND  SUPERFICIAL  MUSCLES  OF  FOREARM, 

131 


'/'///•:  n;n\T  <>\'  nil-:  I-'URKMIM.  133 

the  ulnar  border  is  in  relation  with  the  Hcxor  c;ir|>i  radialis.  Its  under  surface 
is  in  contact  with  the  brachialis  anticus  and  flexor  sublimis  digitorum  muscles, 
the  median  nerve,  and  ulnar  vessels.  The  inner  head  of  the  muscle  separates  the 
median  nerve  in  front  from  the  ulnar  vessels  behind. 

BLOOD  SUPPLY. — Its  nutriment  is  derived  from  the  radial,  ulnar,  and  anasto- 
motiea  magna  arteries. 

NF.KVK  SUPPLY. — From  the  median  nerve-. 

ACTION. — I'ronates  and  flexes  the  forearm. 

The  flexor  carpi  radialis  arises  by  the  common  tendon  from  the  internal 
condyle,  also  from  the  deep  fascia  and  contiguous  surfaces  of  the  adjacent  inter- 
muscular  septa.  It  passes  down  the  forearm  to  the  radial  side  of  the  front  of  the 
wrist,  where  it  traverses  a  canal  in  the  anterior  annular  ligament  and  a  groove 
upon  the  trapezium,  and  is  ultimately  attached  to  the  anterior  surface  of  the  base 
of  the  metacarpal  bone  of  the  index  finger.  A  small  slip  passes  to  the  base  <>! 
the  metacarpal  bone  of  the  middle  ringer.  The  groove  in  the  trapezium  is  con- 
verted into  a  canal  by  a  fibrous  sheath,  the  canal  being  lined  by  a  synovia!  mem- 
brane.  This  muscle  is  tendinous  in  its  lower  three-fifths;  its  belly  is  full  and 
fusiform.  It  is  superficial,  with  the  exception  of  the  small  portion  of  the  tendon 
which  enters  the  annular  ligament ;  it  lies  upon  the  flexor  sublimis  digitorum, 
the  flexor  longus  pollicis,  and  the  wrist-joint.  Externally,  it  is  in  contact  with 
the  pronator  radii  teres,  and  in  its  lower  half  is  very  near  the  radial  vessels  ; 
internally,  it  lies  against  the  palmaris  longus  muscle,  above.  Above  the  wrist 
the  median  nerve  is  on  the  inner  side  of  its  tendon. 

BLOOD  SUPPLY. — Its  nutriment  is  derived  from  the  radial  artery  and  ulnar 
recurrent  artery. 

NERVE  SUPPLY. — Derived  from  the  median  nerve. 

ACTION. — Its  main  function  is  to  flex  the  wrist  ;  it  also  aids  in  flexion  of  the 
elbow,  and  with  the  hand  supinated  it  aids  in  pronation. 

The  palmaris  longus,  often  absent,  is  slender  and  spindle-shaped.  It  arises  by 
the  common  tendon  from  the  inner  condyle,  also  from  the  deep  fascia  and  the 
adjacent  intermuscular  septa.  Its  slender  tendon  passes  over  the  anterior  annular 
ligament  to  terminate  in  an  expanded  prolongation,  which  is  continuous  with  the 
central  portion  of  the  palmar  fascia,  the  deep  fascia  over  the  thenar  eminence, 
and  the  anterior  annular  ligament  at  the  base  of  that  eminence.  It  is  sub- 
cutaneous, except  at  its  origin,  where  it  is  partly  overlapped  by  the  flexor  carpi 
radialis.  It  lies  upon  the  flexor  sublimis  digitorum,  the  median  nerve,  and 
the  anterior  ligament,  and  is  in  relation  with  the  flexor  carpi  ulnaris  internally, 
and  with  the  flexor  carpi  radialis  externally. 

BLOOD  SUPPLY. — From  the  ulnar  artery. 


i:U  Sn«iK'M<   ANATOMY. 

XKIIVK  Srpri.Y. — From  the  median  nerve. 

ACTION. — It  makes  tense  the  palmar  fascia.  Ilexes  (lie  wrist,  and  aids  slightly 
in  elbow  flexion. 

Tile  flexor  carpi  ulnaris,  a  long  and  flat  muscle,  embraces  the  outer  side  of 
the  upper  part  of  the  shaft  of  the  ulna.  It  arises  l>y  two  heads — one  by  the  com- 
mon tendon  from  the  internal  condyle,  the  other  from  the  inner  aspect  of  the 
oleeranon  process — and  partly  l>y  an  aponeurosis  continiUMl  down  from  the  upper 
poll  ion  of  the  posterior  border  of  the  ulna.  Fibers  also  arise  from  the  overlying 
deep  fascia  and  the  intermuscular  septum  between  this  muscle  and  the  llexor  sub- 
limis  digitorum.  The  interval  between  the  condyloid  and  oleeranon  heads  is 
spanned  by  a  tendinous  arch,  under  which  pass  the  ulnar  nerve  and  the  posterior 
ulnar  recurrent  artery.  The  muscle  terminates  in  a  tendon  which  runs  along  its 
anterior  margin,  the  lower  fibers  passing  to  the  tendon  obliquely  downward  and 
forward.  It  is  inserted  into  the  pisiform  bone,  with  more  or  less  fibrous  connec- 
tion with  the  anterior  annular  ligament,  the  unciforin  bone,  and  the  base  of  the 
metacarpal  bone  of  the  little  finger.  It  is  the  only  muscle  of  the  forearm  attached 
to  carpal  bones.  Its  anterior  and  inner  surfaces  are  subcutaneous,  and  intimately 
attached  to  the  deep  fascia  over  much  of  their  extent,  especially  near  the  posterior 
border  of  the  ulna.  It  lies  upon  the  flexor  sublimis  digitorum  and  flexor  pro- 
randus  digitorum  muscles,  and  the  ulnar  vessels  and  nerve.  Its  tendon  is  the 
guide  for  ligation  of  the  ulnar  artery,  which  it  overlaps.  Externally,  it  is  in 
contact  with  the  belly  of  the  palmaris  longus  muscle  and  the  ulnar  vessels 
and  nerve. 

lii.ooi)  Sri'i'i.v. — From  the  ulnar  artery. 

NKKVK  STITLV. — From  the  ulnar  nerve. 

ACTION. — It  flexes  and  add  tic  ts  the  hand,  and  slightly  flexes  the  forearm  on 
the  arm. 

Owing  to  its  extensive  connection  with  the  ulna,  this  muscle  can  not  retract 
so  much  as  the  other  muscles  of  this  group  in  amputation  of  the  forearm. 

The  flexor  sublimis  digitorum  (perforatus)  lies  under  the  previously  described 
muscles  and  arises  by  three  heads — one  from  the  humerus,  ulna,  and  radius, 
respectively.  The  humeral  head  arises  from  the  inner  condyle  by  the  common 
tendon  of  the  flexor  muscles,  from  the  internal  lateral  ligament  of  the  elbow-joint, 
and  the  adjacent  intermuscular  septa  ;  the  ulnar  head  arises  from  the  inner  side  of 
the  coronoid  process  of  the  ulna,  just  above  the  origin  of  the  lesser  head  of  the 
pronator  radii  teres;  the  radial  head  arises  from  the  oblique  line  of  the  radius  and 
the  anterior  surface  of  that  bone  to  a  point  below  the  insertion  of  the  pronator  radii 
teres.  The  fibers  pass,  directly  downward  from  the  three  origins  as  a  broad,  thick, 
and  fleshy  mass,  converging  at  about  the  middle  of  the  forearm  into  four  tendons, 


PLATE  XXXVI, 


Muscuio-splral  nr 
Brachialis  anticus  m. — 


Posterior  interosseous  n.- 
Radial  n. 


Radial  recurrent  a.- 

Supinator  brevis  m 
Radial  a. 

Extensor  carpi  radialis  longior  m 
Supinator  longus  m 


Extensor  carpi  radialis  brevior  m 


Radial  n 

Flexor  longus  pollicis  m 
Pronator  quadratus  m. 


Anterior  carpal  a.- 

Flexor  carpi  radialis  tendon 
Palmaris  longus  tendon 
Superficialis  volae  a.- 


Brachialis  anticus  m. 

Loop  between  anastomotica  magnaa. 
and  anterior  ulnar  recurrent  a. 
Median  n. 


Bicipital  fascia(cut) 

Biceps  tendon 
Brachial  a. 


Ulnar  a. 

Pronator  radii  teres  m. 

Flexor  carpi  radialis  m. 
Palmaris  longus  m. 

Flexor  carpi  ulnaris  m. 


Flexor  sublimis  digitorum  m. 


Median  n. 

Outer  tendon  of  flexor 
sublimis  digitorum  m. 

Ulnar  a. 
Ulnar  n. 

Anterior  carpal  a. 


TRIANGLE  OF  ELBOW,  FLEXOR  SUBLIMIS  DIGITORUM  MUSCLE,  RADIAL  ARTERY,  AND  RADIAL  NERVE, 

135 


THE  FRONT  OF   THK   FOllF.ARM.  137 

which  pass  beneath  the  anterior  annular  ligament,  where  they  are  arranged  in  two 
pairs,  one  hehind  the  other.  The  {interior  pair  go  to  the  middle  and  ring  fingers. 
and  the  posterior  pair  to  the  index  and  little  fingers.  The  tendons  are  inserted 
into  the  middle  of  the  sides  of  the  second  phalanges  of  the  four  fingers.  Each 
tendon  splits  to  permit  the  passage  of  the  tendon  of  the  flexor  profniidus  digitorum 
muscle  between  its  segments,  which  will  be  seen  in  the  dissection  of  the  hand. 

This  muscle  is  covered  by  the  pronator  radii  teres,  the  flexor  carpi  radialis, 
the  palmaris  longus,  and  the  flexor  carpi  ulnaris,  also  by  the  radial  vessels  and 
nerve  and  the  deep  fascia.  It  rests  upon  the  flexor  profundus  digitorum,  and  the 
flexor  longus  pollicis,  the  ulnar  vessels  and  nerve,  and  the  median  nerve.  Its  inner 
edge  is  against  the  flexor  carpi  ulnaris.  Externally,  it  is  overlapped  by  the  lower 
end  of  the  pronator  radii  teres. 

BLOOD  SUPPLY. — From  the  radial  and  ulnar  arteries. 

XKRVE  SUPPLY. — From  the  median  nerve. 

ACTION. — It  flexes  the  proximal  interphalangeal,  the  metacarpo-phalangeal, 
and  wrist  joints,  and  assists  slightly  in  flexion  of  the  elbow. 

DISSKCTIOX. —  Displace  the  supinator  longus  outward  in  order  to  expose  the 
radial  artery  and  nerve  in  the  upper  part  of  the  forearm.  Separate-  the  flexor  carpi 
ulnaris  from  the  flexor  sublimis  digitorum  and  study  the  relations  of  the  ulnar 
vessels  and  nerve.  Then  sever  the  pronator  radii  teres,  flexor  carpi  radialis, 
palmaris  longus,  and  flexor  sublimis  digitorum,  about  one  and  one-half  or  two 
inches  below  the  internal  condyle,  without  cutting  the  median  nerve,  ulnar  artery, 
or  ulnar  nerve.  Reflect  these  muscles  in  order  to  obtain  a  vie\v  of  the  structures 
beneath — namely,  the  flexor  profundus  digitorum,  flexor  longus  pollicis,  pronator 
quadra tus,  median  nerve,  ulnar  vessels,  and  anterior  interosseous  vessels  and  nerve. 

The  flexor  profundus  digitorum  arises  from  the  upper  two-thirds  of  the  front 
and  inner  side  of  the  shaft  of  the  ulna,  and  at  its  upper  end  interdigitates  with  the 
brachialis  anticus  in  the  same  manner  as  that  muscle  at  its  origin  does  with  the 
deltoid.  It  also  arises  from  the  inner  side  of  the  coronoid  process  of  the  ulna,  and 
by  the  aponeurosis  from  the  upper  two-thirds  of  the  posterior  hprder  of  the  ulna,  in 
common  with  the  ulnar  origin  of  the  flexor  carpi  ulnaris,  and  from  the  ulnar  half 
of  the  interosseous  membrane.  It  divides  into  four  tendons,  which  pass  down  the 
forearm  and  continue,  side  by  side,  under  the  anterior  annular  ligament,  behind 
the  tendon  of  the  flexor  sublimis  digitorum  to  the  bases  of  the  terminal  phalanges, 
passing  between  the  segments  of  the  tendons  of  the  flexor  sublimis  digitorum.  A 
lumbricalis  muscle  is  attached  to  each  one  of  these  tendons  in  the  palm.  The 
flexor  profundus  digitorum  muscle  lies  beneath  the  flexor  sublimis  digitorum  and 
flexor  carpi  radialis  muscles,  the  ulnar  vessels  and  nerve,  and  the  median  nerve. 
It  rests  upon  the  ulna,  the  interosseous  membrane,  and  the  pronator  quadratus 


138  *ri!(;i(<AL   ANATOMY. 

muscle.  Internally,  it  is  in  contact  with  the  flexor  carpi  ulnaris ;  and  externally, 
with  the  anterior  interosseous  artery  and  nerve,  ami  the  flexor  longus  pollicis. 

BLOOD  SriTi.Y. —  Derived  from  the  nlnar  and  anterior  intcrosseous  arteries. 

NKKVK  SUPPLY. — From  the  nlnar  nerve,  and  the  anterior  interosseous  branch 
of  tlie  median  nerve. 

ACTION. — It  flexes  the  terminal  phalanges,  and  also  the  interphalangeal, 
metacarpo-phalangeal,  and  wrist  joints. 

The  flexor  longus  pollicis  arises  from  the  front  of  the  shaft  of  the  radius. 
between  the  tnberosity  and  oblique  ridge  above  and  the  insertion  of  the  pronator 
quadratus  below,  and  from  the  adjacent  interosseous  membrane:  at  times  also  by  a 
small  slip  from  the  internal  eondyle  of  the  hnmerus  or  from  the  inner  side  of  the 
eon  moid  process  of  the  ulna,  adjoining  the  insertion  of  the  brachialis  anticus.  It 
passes  down  the  radial  side  of  the  forearm  to  about  its  middle,  where  it  terminates  in 
a  flattened  tendon,  which  passes  under  the  anterior  annular  ligament  and  between 
the  two  heads  of  the  flexor  brevis  pollicis,  to  be  attached  to  the  base  of  the  last 
phalanx  of  the  thumb.  It  lies  beneath  the  flexor  snblimis  digitornm,  the  supinator 
1  nii^-ns,  the  tendon  of  the  flexor  carpi  radialis,  and  the  radial  vessels  and  nerve, 
and  rests  upon  the  radius,  the  interosseous  membrane,  and  the  pronator  quadratus. 
I  '[ion  its  nlnar  side  lie  the  flexor  profundus  digitorum,  the  anterior  interosseous 
artery  and  nerve;  and  upon  the  radial  side  are  the  supinator  brevis,  the  insertion 
of  the  pronator  radii  teres,  the  radial  origin  of  the  flexor  sublimis  digitornm,  and 
the  tendons  of  the  supinator  longus  and  extensores  carpi  radialis  longior  and 
brevior. 

BLOOD  SUPPLY. — From  the  radial  and  anterior  interosseous  arteries. 

NERVE  SUPPLY. — From  the  anterior  interosseous  nerve. 

ACTION. — It  flexes  the  terminal  phalanx  of  the  thumb,  and,  to  a  slight  extent, 
the  first  phalanx. 

The  pronator  quadratus  is  a  flat,  square  muscle,  which  lies  in  front  of  the 
lower  ends  of  the  radius,  ulna,  and  interosseous  membrane.  It  arises  from  the 
oblique  ridge  on  the  anterior  surface  of  the  lower  fourth  of  the  ulna,  and  from  the 
aponeurosis  covering  the  inner  one-third  of  the  muscle ;  thence  its  fibers  cross 
the  forearm  transversely  and  somewhat  obliquely  for  insertion  into  the  outer 
border,  anterior  and  internal  surfaces  of  the  lower  fourth  of  the  radius.  It  rests 
upon  the  radius,  ulna,  interosseous  membrane,  and  the  anterior  interosseous 
vessels  and  nerve,  and  is  covered  by  the  tendons  of  the  flexor  profundus  digi- 
torum, flexor  longus  pollicis,  flexor  carpi  radialis,  and  the  radial  and  ulnar 
vessels  and  ulnar  nerve. 

BLOOD  SUPPLY. — Derived  from  the  anterior  interosseous  artery. 

NERVE  SUPPLY. — From  the  anterior  interosseous  nerve. 


PLATE  XXXVII. 


..I  n. — 
CUB  m 

Supmator  iongus  m  .(displaced) 

Posterior  inte.osseous  n. 
Biceps  tendon 

Radial  recurrent  a 

Supmator  brevis  m.' 
Radial  n. 

Extensor  carpi  radialis  longior 
Anterior  interosseous  a, 
Radial  a 

Extensor  carpi  radialis  brevior  m 
Pronator  radii  teres  m. 


Radial  origin  of  flexor  sublimts  digito 


Flexor  Iongus  pollicis  m. 


Pronator  quadratus 


Extensor  ossis  metacarpi  poMlcis  tend 

Anterior  carpal  a. 
Superficies  vol, 
Extensor  primi  internodii  pollicis  ten 


Abductor  poUicU  m. 
Opponens  pollicis  m. 

Outer  head  of  flexor  brevis  pollicis  m 

Inner  head  of  flexor  brevis  pollicis  m 

% 
Adductor  pollicis  m/ 

Abductor  indicis  m, 

Flexor  Iongus  pollicis  tendon 

Princeps  pollicis  a. 

Radialis  indicts  a. 


Branch  of  anastomtca  magna  a. 

Median  n. 

Bicipital  fascia 

Brachialis  anticus  m, 
Brachial  a, 

.Anterior  ulnar  recurrent  a. 
Coronoid  head  of  pronator  radii  teres  m 

Posterior  ulnar  recurrent  a. 

Common  interosseous  a. 

—  Posterior  interosseous  a. 

Flexor  carpi  ulnaris  m.(displactd) 

Flexor  profundus  digitorum  m. 
Median  a. 
Ulnar  n. 


utaneous  branch  of  ulnar  n. 


or  carpal  a- 

branch  ulnar  n. 
p  branch  ulnar  a. 

ween  median  n.and  ulnar  n. 

Abductor  minimi  digiti  m. 
exor  brevis  minimi  digiti  m. 

LumbricaleS  muscles 


Interosseous  a. 

Digital  a. 

r  subljmis  digitorum  tendon 

Collateral  digital  a. 


DEEP  FLEXOR  MUSCLES,  RADIAL  ARTERY  AND  NERVE  ULNAR  ARTERY  AND  NERVE,  AND  MEDIAN  NERVE. 

140 


PLATE  XXXVIII. 


Supmator  longus  m. 
Musculo-spi 

Brachia(is  anticus  m. 

Brachial  a 

Posterior  interosseous  n 

Radial  n. 

Radial  reccurrent  a, 

Supinator  brevis  m. 

Radial  a.- 

Extensor  carpi  radiatis  longior  m 

Supinator  tongus  m. (displaced) 

Extensor  carpi  radialis  brevier  m 
Pronator  radii  teres  m.(cut)  — 


Radial  origin  of  flexor  sublimus  digitorum 


Flexor  longus  pollicis  m. 

Anterior  ir.terosseous  3, piercing  interosseous  membrane 

Radial  n. 


Anterior  carpal  & 
Superficial  volae  a. 


Abductor  pollicis  m.fcut) 
Opponens  pollicis  m 


Abductor  indicis  m. 


Radialis  indicis  a 

Lumbrical  m.(cut) 
Princeps  pollicis  a. 


Branch  of  anastomotica  magna  a. 
Median  n. 


achialis  anticus  m. 
Bicipital  fascia . 

Condyloid  origin  of  flexors 
Biceps  U 


Coronoid  head  of  pronator  radii  teres  m. 
Anterior  ulnar  recurrent  a. 

Posterior  ulnar  recurrent  a. 
Anterior  interosseous  n. 

Common  interoseous  a. 
Posterionnterosseous  a. 


Anterior  interosseous  a.- 

He/or  carpi  utnaris  m. (displaced) 


Ulnar  n. 
Ulnar a. 
Flexor  profundus  digitorum  m. (displaced) 


nterosseous  membrane. 


Dorsal  cutaneous  branch  of  ulnar  n. 

Pronator  quadratus  m.(cut) 
Anterior  branch  of  anterior  interosseous  a. 


Deep  branch  of  ulnar  n. 
Deep  branch  of  ulnar  a. 

Flexor  brevis  minimi  digiti  m.(cut) 
Deep  branch  of  ulnar  n. 
Deep  palmar  arch. 
Opponens  minimi  digit!  m. 

Abductor  minimi  digiti  m. 

Interosseous  m. 
Adductor  pollicis  m.(cut) 

Interosseous  a. 
Digital  a. 


ARTERIES  AND   NERVES  OF  FRONT  OF  FOREARM. 
141 


TUI-:  FRONT  or  TIU-;  F 

ACTION. — It  pronates  the  forearm. 

Tlic  interosseous  membrane  extends  between  the  intcrosseous  margins  ut'  the 
radius  iind  ulna,  firmly  connecting  the  shafts  of  those  hones  and  forming  a  divid- 
ing wall  hetween  the  front  and  the  hack  of  the  forearm.  It  extends  upward  to 
within  an  inch  of  the  tuherosity  of  the  radius,  and  downward  to  the  inferior  radio- 
ulnar  articulation.  Its  fibers  pass  downward  and  inward  from  the  edge  of  the 
radius  to  the  radial  margin  of  the  ulna.  It  affords  attachment  to  the  dee])  muscles 
of  the  front  and  hack  of  the  forearm,  supports  the  anterior  inferosseous  artery  and 
its  vena-  eomites,  and  the  anterior  interosseons  nerve.  The  anterior  interosseous 
artery  pierces  the  membrane  about  one  and  one-half  inches  above  its  lower  end. 
It  is  relaxed  in  pronation  of  the  forearm.  The  posterior  interosseous  vessels  pass 
backward  above  its  upper  margin. 

The  oblique  ligament  is  a  round,  fibrous  cord,  connected  above  to  the  tubercle 
of  the  ulna  located  at  the  base  of  its  coronoid  process,  whence  it  extends  down- 
ward and  outward  to  the  radius  to  a  point  a  little  below  the  bicipital  tuherosity. 
It  is  connected  by  a  thin  membrane  to  the  upper  border  of  the  interosseous 
membrane.  Its  direction  forms  a  right  angle  with  that  of  the  fibers  of  the 
interosseous  membrane.  Sometimes  it  is  absent. 

Tlie  radial  artery  begins  at  the  bifurcation  of  the  brachial,  about  one-half  of 
an  inch  below  the  elbow-joint.  Its  course  is  more  nearly  in  a  direct  line  with  the 
parent  trunk  than  is  that  of  the  ulnar  artery,  and  is  represented  by  a  line  drawn 
from  a  point  one-half  of  an  inch  below  the  middle  of  the  bend  of  the  elbow  to 
the  inner  side  of  the  base  of  the  styloid  process  of  the  radius.  It  passes  down 
the  radial  side  of  the  forearm  along  the  ulnar  margin  of  the  supinator  longus, 
which  is  the  muscle  of  reference  for  its  ligation,  and  is  overlapped  thereby  in 
the  upper  one-third  or  one-fourth  of  its  course.  At  the  wrist  or  base  of  the 
thumb  it  turns  backward  over  the  external  lateral  ligament  of  the  wrist-joint 
beneath  the  extensors  of  the  thumb,  and  then  passes  between  the  two  heads 
of  the  first  dorsal  interosseous  muscle  (abductor  indicia)  into  the  palm  of 
the  hand,  where  it  assists  in  forming  the  deep  palmar  arch.  It  is  superficial 
in  the  forearm,  except  at  its  upper  part,  where  it  is  covered  by  the  supinator 
longus.  From  above  downward  it  rests  upon  the  tendon  of  the  biceps,  the 
supinator  brevis,  the  pronator  radii  teres,  the  radial  head  of  the  flexor  sublimis 
digitorum,  the  flexor  longus  pollicis,  the  pronator  quadratus,  the  radius,  and 
the  external  lateral  ligament  of  the  wrist-joint.  In  its  upper  one-third  it  lies 
between  the  supinator  longus  and  the  pronator  radii  teres;  while  in  its  lower 
two-thirds  it  passes  between  the  tendons  of  the  supinator  longus  and  flexor  carpi 
radialis.  It  is  accompanied  by  its  vena>  eomites,  and  at  its  middle  one-third  has 
the  radial  nerve  upon  its  outer  side.  Filaments  of  the  musculo-cutaneous  nerve  are 


Ill  SURGICAL    ANATOMY. 

closely  related  to  its  lower  part  as  it  courses  around  the  wrist.  Its  branches  in  ihe 
forearm  are  the  radial  recurrent,  muscular,  superficialis  vohe,  and  the  anterior 
carpal:  at  the  wrist,  the  posterior  carpal,  the  metacarpal,  the  dorsalis  pollicis, 
and  the  dorsalis  indicis ;  and  in  the  hand,  the  princeps  pollicis.  radialis  indicis, 
perforating,  palmar  interosseous,  and  recurrent  carpal.  We  will,  at  ihis  lime,  con- 
sider only  ihose  branches  given  oil'  in  the  forearm. 

The  radial  recurrent  arises  from  the  outer  side  of  ihe  radial  arterv,  passes 
downward  between  the  supinator  brevis  and  supinator  longus  muscles  and  lietwcen 
the  radial  and  posterior  interosseous  nerves  ;  thence  upward,  in  company  with  the 
musculo-spiral  nerve,  between  the  brachialis  anticus  and  supiualor  longus,  both  of 
which  it  in  part  supplies.  It  anastomoses  with  the  terminal  branches  of  the 
superior  profunda  in  front  of  the  external  eondyle  and  between  the  two  last-named 
muscles.  From  its  arch  it  sends  muscular  branches  to  the  supinator  and  the 
extensor  muscles,  some  passing  beneath  the  latter  to  anastomose  with  the  inter- 
osseous recurrent  branch  of  the  posterior  interosseous.  It  also  supplies  the  elbow- 
joint. 

The  muscular  branches  arise  from  the  radial  in  its  downward  course  and 
supply  the  muscles  upon  the  radial  side  of  the  forearm. 

The  superficialis  volae  arises  from  the  radial  artery  near  the  wrist,  and  passes 
over  the  ball  of  the  thumb.  Sometimes  it  runs  beneath  the  abductor  pollicis 
muscle.  It  supplies  the  muscles  of  the  ball  of  the  thumb  and  often  anastomoses 
with  the  ulnar  artery  to  assist  in  the  formation  of  the  superficial  palmar  arch. 
When  the  superficialis  vola3  arises  higher  than  visual  and  runs  beside  the  radial, 
it  would  give  the  palpating  finger  the  sensation  of  a  double  pulse. 

The  anterior  carpal  arises  from  the  radial  artery  near  the  lower  margin  of 
the  pronator  qnadratus,  whence  it  passes  inward  to  anastomose  with  the  anterior 
carpal  branch  of  the  ulnar  artery,  thus  forming  a  prc-carpal  loop, — the  anterior 
carpal  arch, — from  which  branches  descend  to  nourish  the  wrist-joint.  The 
posterior  carpal,  metacarpal,  dorsalis  pollicis,  and  dorsalis  indicis  will  be  described 
with  the  back  of  the  wrist  and  hand. 

The  ulnar  artery,  larger  than  the  radial,  is  the  other  terminal  branch  of  the 
brachial  artery.  It  at  once  turns  toward  the  ulnar  side  of  the  forearm,  and  readies 
it  one-third  of  the  way  down,  after  which  it  skirts  the  ulnar  border  of  the  forearm 
to  the  wrist.  A  line  drawn  from  a  point  one-half  of  an  inch  below  the  middle  of 
the  bend  of  the  elbow  to  the  junction  of  the  upper  with  the  middle  one-third  of  the 
ulnar  border  of  the  forearm  will  represent  the  course  of  the  upper  or  deep  portion 
of  this  vessel.  A  line  drawn  from  a  point  midway  between  the  internal  eondyle 
and  the  middle  of  the  bend  of  the  elbow  to  the  radial  side  of  the  pisiform  bone 
will  represent  the  course  of  the  artery  in  the  lower  two-thirds  of  the  forearm.  It 


PLATE  XXXIX, 


Inferior  profunda  a. 


Anastomotica  magna  a. 


Posterior  ulnar  recurrent  a. 
Anterior  ulnar  recurrent  a. 


Common  Interosseous  a. 
Anterior  interosseous  a. 

Ulnar  a 


Anterior  carpal  a. 
Posterior  carpal  a. 

Recurrent  carpal  a 
Deep  palmar  arch 


Palmar  Interosseous  a 

Superficial  palmar  arch 
Dorsal  interosseous  a. 


10 


achial  a. 


Superior  profunda  a, 


Radial  recurrent  a. 


Interosseous  recurrent  a. 
Radial  a 
Oblique  ligament 

Posterior  interosseous  a. 


nterosseous  membrane 


Anterior  carpal  a. 
Superficialis  volae  a. 


Dorsalis  pollicis  a. 
Posterior  carpal  a. 


Priceps  pollicis  a. 
Dorsalis  indicis  a. 
Radial  indicis  a. 
Digital  a. 
Meta  caroal  a. 


ARTERIES  OF.  FOREARM  AND  HAND. 
145 


THE    /•7,'O.VV   OF   Till-:   FOHK.IHM.  1-47 

crosses  the  anterior  annular  ligament  on  the  radial  side  of  the  pisiform  bone,  and 
runs  across  the  palm,  forming  the  superlicial  palmar  arch,  which  is  usually  com- 
pleted by  anastomosis  with  the  superlicialis  vohe.  The  ulnar  artery  is  dec])  in  its 
upper  half,  being  covered  hy  all  of  the  superficial  flexors  except  the  flexor  carpi 
ulnaris ;  in  its  lower  half  it  is  more  superficial,  being  overlapped  hy  the  tendon  of 
the  flexor  carpi  ulnaris,  while  immediately  above  the  wrist  it  is  subcutaneous,  and 
lie--  between  the  tendon  of  the  flexor  carpi  ulnaris  and  the  innermost  tendon  of  the 
flexor  sublimis  digitorum.  It  lies,  from  above  downward,  upon  the  braehialis 
anticus,  flexor  profnndus  digitorum, and  the  anterior  annular  ligament.  It  has  two 
vena-  eomites.  At  its  upper  part  the  median  nerve  crosses  in  front  of  it,  while  the 
ulnar  nerve  is  upon  the  inner  side  of  its  lower  two-thirds.  In  the  upper  third  of 
the  course  of  the  artery  the  ulnar  nerve  lies  some  distance  to  its  ulnar  side.  When 
the  ulnar  artery  has  a  high  origin  from  the  brachial,  it  usually  lies  upon  the 
superficial  flexor  muscles,  instead  of  beneath  them,  and  is  thus  more  liable  to 
injury.  Its  branches  in  the  forearm  are  the  anterior  ulnar  recurrent,  posterior 
ulnar  recurrent,  common  interosseous,  and  muscular;  at  the  wrist,  the  anterior  and 
posterior  carpal ;  in  the  hand,  the"  deep  or  communicating  branch  ;  it  continues  as 
the  superficial  palmar  arch.  As  in  the  case  of  the  radial  artery,  we  will  now 
consider  only  the  branches  given  off  in  the  forearm. 

The  anterior  ulnar  recurrent  artery  arises  from  the  ulnar,  immediately 
below  its  origin,  and  passes  inward  and  upward  upon  the  braehialis  anticus, 
and,  behind  the  pronator  radii  teres,  to  the  front  of  the  inner  condyle  of  the 
humerus,  where  it  anastomoses  with  the  anastomotica  magna  and  the  inferior 
profunda  arteries. 

The  posterior  ulnar  recurrent  artery,  larger  than  the  anterior  ulnar  recur- 
rent, arises  below  that  vessel  and  passes  inward  and  backward  under  the  flexor 
sublimis  digitorum.  It  then, courses  between  the  two  heads  of  the  flexor  carpi 
ulnaris,  in  relation  with  the  ulnar  nerve,  to  the  back  of  the  inner  condyle.  It 
supplies  the  elbow-joint,  ulnar  nerve,  and  adjacent  muscles,  and  anastomoses  with 
the  inferior  profunda,  anastomotica  magna,  and  interosseous  recurrent  arteries. 

The  common  interosseous  artery  is  the  largest  and  shortest  branch  of  the 
ulnar.  It  is  given  off  opposite  the  tuberosity  of  the  radius,  whence  it  passes 
downward  and  outward  to  the  upper  margin  of  the  interosseous  membrane  and 
divides  into  the  anterior  and 'posterior  interosseous  arteries. 

The  anterior  interosseous  artery,  accompanied  by  vena?  eomites  and  the 
anterior  interosseous  nerve,  descends  along  the  middle  of  the  front  of  the 
interosseous  membrane,  between  the  flexor  longus  pollicis  and  the  flexor  pro- 
fundus  digitorum,  and  supplies  nutrient  branches  to  both  muscles  and  to  the 
radius  and  ulna.  It  eventually  perforates  the  interosseous  membrane,  beneath 


MS  xrilGICAL   ANATOMY. 

the  upper  border  of  the  pronator  quadratus.  to  reach  tlic  back  of  the  forearm. 
I'nder  the  upper  border  of  the  pronator  <|iiadratus  it  gives  oil'  a  hranch  which 
supplies  tliis  muscle  and  anastomoses  with  the  anterior  carpal  branches  of  the 
radial  and  nlnar  and  the  recurrent  carpal  branches  of  the  deep  palmar  arch.  In 
the  upper  part  of  the  forearm  it  also  gives  of]'  a  long  slender  branch  which 
accompanies  the  median  nerve  and  is  called  the  comes  nervi  mediani,  or  median 
<ir/<ri/.  This  is  sometimes  quite  large,  and  then  assists  in  the  formation  of  the 
superficial  palmar  arch.  The  posterior  interor-seous  will  be  described  with  the 
back  of  the  forearm. 

The  iinixcii/iir  lii'iincln-x,  variable  in  number,  supply  the  adjacent  muscles. 

The  anterior  carpal  artery  is  a  small  branch  given  off  immediately  above  the 
anterior  annular  ligament.  It  passes  outward,  beneath  the  tendons  of  the  flexor 
profundus  digitorum,  and  anastomoses  with  the  anterior  carpal  branch  of  the  radial, 
with  derivatives  of  the  anterior  interosseons.  and  the  recurrent  carpal  branches  of 
the  deep  palmar  arch.  It  forms,  with  the  corresponding  branch  of  the  radial,  the 
pre-carpal  arch.  The  posterior  carpal  branch  will  be  described  with  the  back  of 
the  wrist  and  hand. 

The  median  nerve  enters  the  forearm  upon  the  inner  side  of  the  brachial 
artery,  passes  between  the  two  heads  of  the  pronator  radii  teres,  the  deep  head  of 
which  separates  it  from  the  ulnar  artery,  and  continues  straight  down  the  forearm 
to  the  wrist,  upon  the  flexor  profundus  digitorum,  covered  by  the  flexor  sublimis 
digitorum.  Near  the  wrist  it  lies  between  the  outer  tendon  of  the  flexor  sublimis 
digitorum  and  the  tendon  of  the  flexor  carpi  radialis ;  it  then  passes  under  the 
anterior  annular  ligament,  resting  upon  the  flexor  tendons.  It  is  accompanied  and 
supplied  by  the  median  artery.  In  the  forearm  it  gives  off  articular,  muscular, 
anterior  interosseous,  and  palmar  cutaneous  branches. 

The  articular  branches,  two  in  number,  supply  the  elbow-joint. 

The  muscular  branches  supply  the  pronator  radii  teres,  the  flexor  carpi  radialis, 
the  palmaris  longus,  and  the  flexor  sublimis  digitorum. 

The  anterior  interosseous,  the  longest  branch  of  the  median,  arises  beneath 
the  upper  part  of  the  flexor  sublimis  digitorum,  and  accompanies  the  anterior 
interosseous  artery  between  the  flexor  longus  pollicis  and  flexor  profundus  digi- 
torum. It  supplies  the  flexor  longus  pollicis,  the  radial  side  of  the  flexor 
profundus  digitorum,  and  the  pronator  quadratus. 

The  palmar  cutaneous  branch  arises  in  the  lower  one-third  of  the  forearm, 
pierces  the  deep  fascia  near  the  anterior  annular  ligament,  and  divides  into  two 
branches,  an  external  and  an  internal,  which  pass  in  front  of  the  ligament.  The 
external  branch  supplies  the  skin  of  the  ball  of  the  thumb  and  communicates 
with  the  musculo-cutaneous  and  radial  nerves ;  the  internal  branch  supplies  the 


PLATE  XL. 


INCISIONS  FOR  DISSECTION. 
150 


THE  FROST   or   Till';   FOREARM.  l~>\ 

skin  of  tln>  palm,  except  on  the  uhiar  side,  and  communicates  with  the  ulnar 
palmar  cutaneous  branch. 

The  radial  nerve  is  one  of  the  terminal  branches  of  the  nmseulo-spiral.  It 
passes  along  the  front  of  the  outer  side  of  the  forearm,  accompanying  the  radial 
artery  along  the  outer  side  of  its  middle  one-third.  In  the  upper  part  of  its 
course  it  is  overlapped  by  the  belly  of  the  snp'mator  longus,  and  about  three  inches 
above  the  wrist  curves  backward  under  the  tendon  of  that  muscle  and  pierces  the 
deep  fascia,  at  the  outer  border  of  the  forearm,  to  divide  into  an  external  and  an 
internal  branch.  These  supply  the  skin  of  the  back  of  the  hand  and  lingers. 

The  ulnar  nerve,  emerging  from  between  the  olecranon  and  the  internal 
enndyle  of  the  humerus  in  the  upper  part  of  the  forearm,  passes  down  the 
anterior  and  inner  side  of  the  forearm  upon  the  flexor  profundus  digitorum  and 
beneath  the  belly  of  the  flexor  carpi  ulnaris,  while  in  the  lower  part  of  its  course 
it  lies  to  the  radial  side  of  the  flexor  carpi  ulnaris  muscle  and  its  tendon. 
It  has  upon  its  radial  side,  as  far  down  as  the  pisiform  bone,  the  lower  two- 
thirds  of  the  ulnar  artery.  While  in  the  forearm  the  ulnar  nerve  gives  off 
articular,  muscular,  cutaneous,  and  dorsal  cutaneous  branches,  and  not  infre- 
quently it  communicates  with  the  median  nerve. 

The  articular  branches  are  given  off,  behind  the  internal  condyle,  to  supply 
the  elbow-joint,  and,  just  above  the  carpus,  to  supply  the  wrist-joint. 

Of  the  muscular  branches,  the  one  to  the  flexor  carpi  ulnaris  arises  in  the 
upper  part  of  the  forearm  ;  the  other  arises  lower  down,  and  passes  to  the  inner 
part  of  the  flexor  profundus  digitorum. 

The  cutaneous  branches  are  two  small  nerves  arising,  by  a  common  trunk,  in 
the  middle  of  the  forearm.  The  shorter,  and  more  superficial,  descends  to  the  skin 
of  the  ulnar  side  of  the  wrist,  pierces  the  deep  fascia,  and  joins  a  branch  of  the 
internal  cutaneous,  while  the  other,  a  deeper  branch,  accompanies  the  ulnar  artery 
lying  upon  its  anterior  surface,  to  supply  the  skin  of  the  ulnar  side  of  the  palm  of 
the  hand.  This  branch  communicates  with  twigs  from  the  median,  and  is  called 
the  palmar  cutaneous  branch. 

The  dorsal  cutaneous  branch  arises  about  three  inches  above  the  wrist  and 
passes  backward,  under  the  flexor  carpi  ulnaris,  to  the  posterior  surface  of  the 
wrist,  where  it  pierces  the  deep  fascia  and  divides  into  a  communicating  and  two 
digital  branches,  which  supply  the  skin  and  fascia  of  the  ulnar  side  of  the  hand, 
both  sides  of  the  little  finger,  and  the  adjacent  side  of  the  ring  finger.  The 
communicating  branch  inosculates  with  the  posterior  branch  of  the  internal 
cutaneous  and  the  digital  branches  with  the  adjacent  ones  from  the  radial  nerve. 


152  SURGICAL   A \ ATOMY. 

THE  FKOXT  OF  Till-:  II  AM). 

DISSECTION. — Tin-  skin  lias  been  incised  across  the  front  of  Ihc  wrist.  From 
the  inner  end  of  Iliis  incision  make  another  along  (lie  ulnar  bonier  of  tlie  |)alin  as 
far  as  the  junction  of  the  latter  with  the  little  linger.  From  the  outer  end  of  the 
transverse  incision  make  a  third  along  the  radial  border  of  the  thenar  eminence  to 
the  base  of  the  first  phalanx  of  the  thumb,  then  around  the  palmar  surface  of  the 
thumb,  and  along  the  radial  border  of  the  palm  to  its  junction  with  the  index 
linger.  The  Hap  of  integument  thus  marked  out  is  reflected  downward,  exposing 
the  superficial  fascia.  In  dissecting  the  thumb  and  fingers  the  skin  is  incised  in 
the  median  line  and  reflected  laterally.  The  skin  of  the  palm  is  sensitive  and 
well  supplied  with  sweat  glands,  sebaceous  glands  being  absent. 

Superficial  fascia. — The  superficial  fascia  of  the  palm  is  dense  and  thin,  and 
closely  connects  i lie  skin  with  the  deep  fascia,  resembling  in  this  respect  that 
of  the  scalp  and  sole  of  the  foot.  That  covering  the  thenar  and  hypothenar 
eminences  is  more  delicate.  The  fat  in  the  palm  of  the  hand  presents  a  somewhat 
lobulated  appearance,  and  when  an  incision  is  made  through  the  skin,  small 
masses  of  adipose  tissue  protrude  through  the  opening.  It  contains  the  palmaris 
biv vis  muscle,  the  ulnar  vessels  and  nerve,  the  palmar  cutaneous  branches  of  the 
ulnar  and  median  nerves,  and  the  superficial  transverse  ligament. 

The  palmaris  brevis  muscle  is  embedded  in  the  granular  superficial  fascia  on 
the  ulnar  side  of  the  palm.  It  consists  of  a  series  of  slightly  divergent  fasciculi, 
which  arise  from  the  central  palmar  fascia  and  the  anterior  annular  ligament,  pass 
OVQT  the  hypothenar  eminence,  and  are  inserted  into  the  skin  of  the  ulnar  border 
of  the  palm. 

NERVE  SUPPLY. — From  the  ulnar  nerve. 

The  ulnar  vessels  and  nerve  occupy  the  superficial  fascia  on  the  radial  side 
of  the  pisiform  bone,  where  their  deep  branches  are  given  off. 

Palmar  cutaneous  nerves. — Trace  the  palmar  cutaneous  branches  of  the 
median,  radial,  and  ulnar  nerves  to  their  termination.  That  of  the  median  passes 
between  the  tendons  of  the  flexor  carpi  radialis  and  palmaris  longus  and  over  the 
anterior  annular  ligament.  It  supplies  the  hollow  of  the  palm  and  the  adjacent 
border  of  the  thenar  eminence.  The  palmar  cutaneous  branch  of  the  ulnar  nerve 
passes  into  the  hand  in  front  of  and  accompanying  the  ulnar  artery,  and  supplies 
the  ulnar  side  of  the  hollow  of  the  palm.  The  radial  palmar  cutaneous  supplies 
the  outer  margin  of  the  thenar  eminence. 

The  superficial  transverse  ligament  is  a  band  of  fibers  which  crosses  the 
roots  and  webs  of  the  fingers  and  connects  the  slips  of  the  central  portion  of  the 
palmar  fascia. 


PLATE  XLI, 


Superficial  fascia 


SUPERFICIAL  PALMAR  FASCIA. 
153 


PLATE  XLII. 


J 


-Palmaris  brevis  m. 


-Deep  palmar  fascia 


'• 


-Dip-ital  a. 


Collateral  digital  n. 


DEEP  PALMAR  FASCIA  AND  PALMARIS  BREVIS  MUSCLE. 
156 


Till-:    ril<L\T  OF    THE  HAM).  1~>7 

DISSKCTIOX. — In  ivinoving  the  superficial  palmar  fascia  begin  at  the  wrist  and 
work  toward  tlic  digital  clefts  and  dissect  it  free  from  (lie  underlying  deep  palmar 
fascia.  This  exposes  fas  anterior  annular  /ii/mm at  of  the  wrist,  a  thickened  band 
of  the  deep  fascia  of  the  forearm,  which  extends  from  the  pisiform  and  the  hook 
of  the  uiiciform  bone,  upon  the  ulnar  side  of  the  wrist,  to  the  tuherosity  of  the 
scaphoid  and  the  ridge  of  the  t rape/him  upon  the  radial  side  of  the  wrist.  It  is 
firm,  dense,  and  unyielding,  gives  origin  to  most  of  the  muscles  of  the  thenar  and 
hypothenar  eminrnn's,  and  converts  the  hollow  of  the  front  of  the  wrist  into  a 
tunnel  for  the  passage  of  some  of  the  structures  of  the  forearm  which  are  destined 
for  the  front  of  the  hand.  It  is  crossed  by  the  following  structures,  enumerated  in 
their  order,  from  the  ulnar  to  the  radial  side  :  The  tendon  of  the  flexor  carpi 
ulnaris,  part  of  which  it  receives  for  insertion;  the  ulnar  nerve,  situated  at  the 
radial  side  of  that  tendon;  the  ulnar  artery  and  its  venae  comites ;  the  palmar 
cutaneous  branches  of  ulnar  and  median  nerves ;  the  palmaris  longus,  part  of 
which  it  receives  for  insertion  ;  and  the  tendon  of  the  flexor  carpi  radialis,  which 
passes  over  its  upper  margin  and  then  pierces  it.  The  tunnel  beneath  the 
ligament  gives  passage  to  the  following  structures:  The  tendons  of  the  flexor 
sublimis  digitorum  and  flexor  profundus  digitorum,  the  tendon  of  the  flexor 
longus  pollicis,  and  the  median  nerve. 

The  great  carpal  or  palmar  bursa. — In  this  tunnel  there  are  two  synovia! 
sacs,  separated  by  the  median  nerve;  the  outer  invests  the  tendon  of  the  flexor 
longus  pollicis  and  extends  upon  the  first  phalanx  of  the  thumb ;  the  inner 
invests  the  tendons  of  the  flexor  sublimis  digitorum  and  flexor  profundus  digito- 
rum and  extends  to  the  middle  of  the  palm.  Upon  the  proximal  two  phalanges 
of  the  fingers  the  flexor  tendons  are  also  invested  by  a  synovial  sheath  which 
lines  their  fibrous  sheaths.  The  synovial  sheath  on  the  little  finger  is  usually 
described  as  being  continuous  with  the  inner  sac  of  the  great  carpal  bursa, 
while  the  synovial  sheaths  on  the  tendons  of  the  index,  middle,  and  ring  fingers 
cease  at  the  heads  of  the  metacarpal  bones  and  do  not  communicate  with 
the  great  carpal  bursa.  The  arrangement  of  these  sheaths  probably  differs 
somewhat  in  individuals.  Schiiller  states  that  only  exceptionally  does  the 
sheath  for  the  little  finger  communicate  with  the  main  or  inner  synovial  sac. 
These  sacs  form  what  is  called  the  great  carpal  bursa,  which  extends  about  an 
inch  into  the  forearm.  The  great  carpal  bursa,  when  distended,  is  constricted 
in  the  middle  by  the  anterior  annular  ligament,  which  gives  it  an  hour-glass  shape. 
Inflammation  of  the  sheath  of  the  flexor  tendon,  over  the  proximal  phalanx 
of  the  thumb,  may,  by  extension,  involve  the  outer  sac  of  the  great  carpal  bursa, 
while  inflammation  of  the  sheath  of  the  flexor  tendons  of  the  little  finger  may 
implicate  the  inner  sac.  When  the  two  sacs  communicate  in  front  of  the  median 


158  SURGICAL  ANATOMY, 

nerve,  which  they  occasionally  do,  inflammation  of  one  is  readily  communicated 
to  the  other.  Purulent  collections  in  the  invent  carpal  hursa  re([iiire  early  and 
live  incision,  with,  in  some  cases,  division  of  the  anterior  annular  ligament. 
Purulent  collections  in  the  sheaths  of  the  ilexor  tendons  of  the  index,  middle, 
and  ring  fingers,  by  reason  of  the  anatomic  condition,  would  not  extend  into 
the  palm  further  than  the  heads  of  the  metacarpal  hones. 

The  deep  palmar  fascia  is  intimately  united  to  the  skin  in  the  middle  of  the 
palm,  and  less  so  at  the  side's.  It  is  divided  for  description  into  a  central  and  two 
lateral  portions.  The  /•< •iifnil  /iniilnii  is  dense  and  strong,  and  protects  the  underlying 
vessels,  nerves,  and  tendons  from  injury.  Its  strength  is  greatest  in  those  who  are 
accustomed  to  handling  heavy  implements.  It  is  triangular  in  shape  and  narrow 
at  its  origin  from  the  lower  border  of  the  anterior  annular  ligament,  where  it  is 
strengthened  by  the  broadened  tendon  of  the  palmaris  longus.  It  expands  in  its 
passage  through  the  palm  to  divide  into  four  digital  slips,  one  going  to  the  base  of 
each  finger;  not  uncommonly  an  additional  slip  passes  to  the  thumb.  Each  slip 
divides  to  permit  the  passage  of  the  digital  flexor  tendons,  the  divisions  being  then 
inserted  into  the  sides  of  the  bases  of  the  first  phalanges  and  the  deep  transverse 
ligament  which  connects  the  heads  of  the  metacarpal  bones  of  the  fingers.  Each 
slip  is  also  continuous  with  the  fibrous  sheath  of  the  ilexor  tendons.  At  the  point 
of  division  into  its  four  digital  processes,  the  fascia  is  strengthened  by  transverse 
fibers.  Through  the  spaces  between  the  primary  divisions  of  the  fascia  pass  the 
digital  vessels  and  nerves  and  the  lumbricales  tendons.  This  central  portion  of 
the  palmar  fascia  is  closely  united  to  the  skin  of  the  palm  by  many  small,  short, 
fibrous  bands,  which  prevent  the  integumentary  covering  from  being  thrown  into 
folds  and  from  gliding  to  and  fro  during  the  various  movements  of  the  hand. 
From  either  side  of  the  central  portion  a  process  of  fascia  dips  into  the  palm  to 
join  the  deep  transverse  layer  of  fascia  which  covers  the  interossei  muscles,  the  deep 
palmar  arch,  and  the  metacarpal  bones,  thus  separating  the  muscles  of  the  thenar 
and  hypothenar  eminences  from  the  center  of  the  palm.  This  central  fascial  com- 
partment contains  the  superficial  palmar  arch  and  its  branches,  the  digital  branches 
of  the  median  nerve,  the  outer  digital  branch  of  the  ulnar  nerve,  the  superficial  and 
deep  flexor  tendons,  and  the  lumbrical  muscles.  This  fascial  compartment  maybe 
compared  to  a  box  the  ends  of  which  are  open  and  correspond  to  the  tunnel  under 
the  anterior  annular  ligament,  above,  and  to  the  intervals  between  the  primary  and 
secondary  divisions  of  the  central  palmar  fascia,  below.  It  is  of  surgical  signifi- 
cance. A  collection  of  pus  in  this  compartment  would  point  in  the  forearm  above 
the  anterior  annular  ligament,  at  the  clefts  of  the  fingers,  or  upon  the  dorsum  of 
the  hand  over  the  interosseous  spaces,  rather  than  upon  the  palm,  because  of  the 
density  of  the  central  palmar  fascia.  The  deep  transverse  layer  of  the  palmar 


PLATE  XLIII. 


Radial  a 


S'jperficiaiis  vof'ae  a 

Outer  head  of  flexor  brevis  pollicis 

Abductor  pollicis  m.  . 

Opponens  poliicis  m. 

Inner  head  of  flexor  brevis  pollicis 

Adductor  pollicis  m. 

Tendon  o*  flexor  longus  pollic 


Umar  a. 
Ulnar  n. 


Palrparfi  iongus  tendon 

Deop  branch  of  ulnar  n. 

Deep  b'anch  of  ulnar  a 
Anterior  annular  ligament 
Abductor  minim'  digiti  m, 

Loop  between  median  and  ulner  nerves 
Flexor  brevis  minimi  digit!  m. 

Superficial  palmar  arch 
Digita1  arteries 

Digital  nerves 


Flexor  subl'mis  digitorum  tendon 
Interosseous  a. 


Collateral  digital  a. 

Collateral  digital  n. 


Flexot  profundus  digitorum 
tendon 


SUPERFICIAL  PALMAR  ARCH  AND  DIGITAL  NERVES. 
159 


THE   1-'1:<>\T  OF   THE  HAM).  161 

fascia  oilers  sonic  resistance  to  the  passage  of  pus  toward  tin1  dorsum  of  the  hand. 
Contraction  of  the  digital  slip,  passing  to  the  ring  or  little  linger,  Ilexes  the  linger 
upon  the  palm  at  tlie  metacarpophalangeal  joint  and  produces  the  deformity 
known  as  Dupuytren's  contraction  of  the  linger.  In  these  cases  Ihe  fibrous  hand 
heroines  prominent  under  the  overlying  skin,  which  often  presents  transverse  folds 
over  the  contracted  fascia.  This  condition  can  only  he  relieved  hy  subcutaneous 
or  open  section  of  the  offending  slip. 

The  lull  rii/  portions  of  the  palmar  fascia  are  thin,  and  continuous  with  the 
central  palmar  fascia  and  the  fascia  of  (lie  dorsum  of  the  hand;  they  cover  the 
muscles  of  the  theiiar  and  hypotheiiar  eminences. 

DISSECTION. — Divide  the  expansion  of  the  palmaris  longus  and  reflect  the 
Central  palmar  fascia  toward  the  lingers,  noting  its  deep  processes  located  upon 
either  side.  The  structures  of  the  palm  now  exposed  are  :  The  superficial  palmar 
arch  and  its  hranches.  the  median  nerve  and  its  divisions,  the  superficial  and  dee], 
flexor  tendons,  and  the  lumhrical  muscles.  Upon  cither  side  of  the  palm  are  the 
muscles  composing  the  thenar  and  liypothenar  eminences. 

The  superficial  palmar  arch  is  formed  hy  the  terminal  part  of  the  ulnar  artery, 
and  is  completed  by  the  superficialis  voloe,  or  a  branch  from  the  radialis  indicis  or 
princeps  pollicis,  and  sometimes,  though  rarely,  by  a  large  median  artery.  It  com- 
mences at  the  lower  border  of  the  pisiform  bone,  where  the  ulnar  artery  gives  off 
the  deep  or  communicating  branch  which  passes  backward  between  the  abductor 
minimi  digiti  and  flexor  brevis  minimi  digiti  muscles  to  complete  the  deep  palmar 
arch.  It  curves  across  the 'palm  to  the  thenar  eminence,  where  it  is  joined  by  the 
branch  or  branches  which  complete  it.  The  convexity  of  the  arch  is  directed 
toward  the  ringers,  its  lowest  point  corresponding  to  a  line  drawn  transversely 
across  the  hand  from  the  lower  border  of  the  strongly  abducted  thumb.  The 
superficial  palmar  arch  lies  upon  the  short  muscles  of  the  little  finger,  the 
flexor  tendons,  and  the  digital  branches  of  the  median  nerve,  and  is  covered  by  the 
palmaris  brevis,  the  palmar  cutaneous  branches  of  the  median  and  ulnar  nerves, 
and  the  central  palmar  fascia.  Its  branches  are  the  four  digital  arteries. 

The  digital  branches  arise  from  the  convexity  of  the  arch ;  they  supply  the 
nlnar  side  of  the  little  finger,  and  the  adjacent  sides  of  the  little,  ring,  middle, 
and  index  fingers.  The  first  digital  artery  is  joined  by  a  branch  from  the  deep 
palmar  arch  and  passes  over  the  liypothenar  eminence,  to  which  it  sends 
hranches,  and  under  the  inner  digital  branch  of  the  ulnar  nerve.  It  supplies  the 
ulnar  side  of  the  little  finger.  The  second,  third,  and  fourth  dif/ital  arteries  pass  to 
the  intervals  between  the  fingers,  where  they  are  joined  by  the  interosseous  branches 
of  the  deep  palmar  arch  and  anterior  perforating  branches  of  the  dorsal  interosseous 
arteries  and  divide  beneath  the  superficial  transverse  ligament,  about  one-quarter  of 
11 


ir.i>  vriUiH'AL    ANATOMY. 

an  inch  above  tin-  clefts  of  the  tinkers,  into  two  collateral  digital  brandies  tor  the 
supply  uf  the  adjacent  sides  of  the  lingers.  At  their  commencement  they  lie  over  the 
superficial  lle.xor  tendons  ;  hut  as  they  approach  the  clefts  of  the  lingers,  thev  course 
between  them  in  company  with  the  digital  nerves,  and  also  between  the  primary 
slips  of  the  central  palmar  fascia  with  the  nerves  superficial  to  the  arteries.  As 
the  digital  arteries  lie  over  the  interosseous  spaces,  palmar  abscesses  should  be 
opened  in  the  line  of  (be  melacarpal  bones.  1'pon  the  side  of  the  finder  the  col- 
lateral digital  artery  is  behind  the  nerve.  The  collateral  digital  arteries  of  each 
finger  unite  to  form  an  arch  across  the  front  of  the  finger  a  little  beyond  the 
terminal  joint,  and  from  this  arises  an  arterial  plexus  which  supplies  the  pulp  of 
the  end  of  the  finger  and  the  matrix  of  the  nail.  Small  twigs  go  to  the  inter- 
phalangeal  joints,  the  integument  and  sheaths  of  the  tendons,  and  form  arterial 
plexuses,  one  being  in  front  of  each  joint. 

The  ulnar  nerve  crosses  the  wrist  in  front  of  the  .interior  annular  ligament 
upon  the  ulnar  side  of  the  ulnar  artery,  between  the  artery  and  the  pisiform  and 
unciform  bones,  where  it  rests  in  a  groove  between  these  bones  protected  thereby 
from  pressure.  It  divides  into  a  superficial  and  a  dee])  branch.  The  superficial 
branch  passes  along  the  ulnar  side  of  the  palm,  supplying  the  skin  of  this  region 
and  the  palmaris  brevis  which  covers  it.  It  divides  into  a  communicating  and 
two  digital  branches.  The  inner  digital  branch  supplies  the  inner  side  of  the  little 
linger;  the  outer  divides  into  collateral  digital  branches  to  supply  the  adjacent 
sides  of  the  little  and  ring  fingers.  The  communicating  branch  joins  the  inner- 
most digital  branch  of  the  median  nerve.  The  deep  branch  of  the  ulnar  nerve 
accompanies  the  profunda  branch  of  the  ulnar  artery,  and  passes  backward 
between  the  abductor  and  flexor  brevis  minimi  digiti  muscles,  through  the  oppo- 
nens  minimi  digiti,  and  upon  the  distal  side  of  the  deep  palmar  arch. 

It  supplies  the  short  muscles  of  the  little  finger,  all  of  the  interossei,  the  two 
ulnar  lumbricales,  the  adductor  pollicis,  and  the  inner  or  deep  head  of  the  flexor 
brevis  pollicis. 

The  median  nerve  enters  the  hand  beneath  the  anterior  annular  ligament 
enveloped  by  the  synovial  sheaths  of  the  flexor  tendons  of  the  hand  ;  it  ivsts  upon 
the  tendons,  spreads  out  slightly,  and  bifurcates  into  an  external  and  an  internal 
division  as  it  emerges  from  under  the  ligament. 

The  r.iii'i'iiii/  <l!ri.-<ii>ii  gives  off  muscular  branches  to  the  abductor  and 
opponens  pollicis,  and  outer  head  of  the  flexor  brevis  pollicis,  after  which  it 
divides  into  two  digital  branches;  the  /iiitrnnoxl  supplies  a  collateral  branch  to 
either  side  of  the  thumb,  while  the  iinicrnn^t  goes  to  the  radial  side  of  the  index 
finger  and  sends  a  small  twig  to  the  first  lumbrical  muscle. 

The   internal  division,  larger  than  the  external,  divides  into  an  outer  and 


PLATE  XLIV. 


Supirator  longus  m 

MuSCUlo-Spr 


Brachialis  ar.t 


Brachial  a. 

Posterior  interosseous 

Radial  n 


Radial  reccurrent  a. 
Supinator  brevis  m. 
Radial  a. 


Extensor  carpi  < 

Supinator  longus  m. (displaced) 

Extensor  carpi  radialis  brevtor  m 
Pronator  radii  teres  m  (cut1- 


Radial  origin  of  flexor  sublimus  digitor 


Radial  n 


Flexor  longus  pollicis 

Anterior  Interosseous  a, piercing  intero 


Anterior  carpal  ft. 
Superficialis  volae  a. 


Abductor  pollicis  m/cut) 
Opponens  pollicis  m. 


Abductor  indicis  m 


Radialis  indicis  a.— 

Lumbrica!  m.(cut) 
Princeps  pollicis  a. 


ch  of  anastomotica  magna  a. 

ian  n. 

rachialis  anticus  m . 
fascia. 

ondylotd  origin  of  flexors 
iceps  tendon. 


ad  of  pronator  radii  teres  m. 
.nterior  ulnar  recurrent  a. 

'osterior  ulnar  recurrent  a. 

nterior  interosseous  n. 

ommon  interoseous  a. 
'osterior  interosseous  a. 


iterior  interosseous  a. 

exor  carpi  ulnaris  m. (displaced) 


nar  n. 
nar  a, 
or  profundus  digitorum  m. (displaced) 


eous  membrane. 

taneous  branch  of  ulnar  n. 


uadratus  m.  (cut) 

anch  of  anterior  interosseous  a. 


nch  of  ulnar  n. 
anch  of  ulnar  a. 

brevis  minimi  digiti  m.( 
branch  of  ulnar  n. 

p  palmar  arch. 

•onens  minimi  digiti  m. 

uctor  minimi  digiti  m. 

•erosseous  m , 
Adductor  pollicis  m.(cut) 

terosseous  a. 
Digital  a. 


ARTERIES  AND  NERVES  OF  FRONT  OF  FOREARM. 
163 


PLATE  XLV, 


Flexor  profundus 
digitorum  tendon  - 

Flexor  sublimis 
digitorum  tendon" 


Transverse  metacarpal  iig._ 


Vaginal  or  fibrous  sheath- 


Flexor  sublimis  digitorum 
tendon 

Flexor  profundus  digitorum 
tendon 


Theca  reflected  upon  flexor 
tendons 


Fibrous  sheath 
(everted) 


Ligamenta  longa 


Ligamenta  brevia 


Great  carpal  bursa  anti 


FIBROUS  AND  SYNOVIAL  SHEATHS  OF  FLEXOR  TENDONS. 
166 


THE  mo\T  or  rni-:  IIA.\D.  i<>7 

an  inner  digital  branch.  Tin-  outer  digital  sends  a  branch  to  the  second  hinihrical 
muscle  and  divides  into  two  collateral  branches,  which  supply  the  adjacent  sides 
of  the  index  and  middle  fingers  as  well  as  the  dorsnm  of  these  lingers.  The  inner 
digital,  in  addition  to  communicating  with  the  nlnar  nerve,  divides  into  two 
collateral  branches,  which  supply  the'  adjacent  sides  of  the  middle  and  ring  lingers, 
and  also,  occasionally,  the  third  Inmhrical  muscle.  Kach  collateral  branch  sends 
branches  to  the  dorsnm  of  the  tinkers,  and  that  of  the  middle  linger  is  almost 
entirely  supplied  by  these  nerves. 

At  first  the  digital  nerves  are  beneath  the  snpevlici.il  palmar  arch  and  the 
digital  branches  arising  therefrom,  but  they  gradually  become  more  superficial, 
and,  along  the  sides  of  the  lingers,  lie  in  t'vont  of  the  collateral  digital  avteries. 
At  the  tips  of  tlie  lingers  they  give  oil'  anterior  twigs  to  supply  the  pulp  of  the 
linger,  and  on  the  posterior  aspect,  twigs  which  supply  the  matrix  of  the  nail. 
Very  careful  dissection  discovers,  upon  the  liner  ramifications  of  the  collateral 
branches  of  the  digital  nerves,  minute  seed-like  enlargements  known  as  the 
J'acinian  bodies — a  form  of  nerve  terminus. 

The  flexor  tendons  cross  the  wrist  in  a  large  compartment  beneath  the 
anterior  annular  ligament,  the  outermost  being  that  fov  the  jlr.rnr  Imii/nx  pul/irix, 
which  pusses  outward  along  the  thumb.  The  four  tendons  of  the  jli.rm-  xn/,lii/iix 
ilif/itarnii)  lie  in  the  tunnel  beneath  the  anterior  annular  ligament,  arranged  in  two 
pairs,  one  being  anterior  to  the  other.  The  anterior  pair  go  to  the  middle  and 
ring  fingers:  the  posterior,  to  the  index  and  little  fingers.  Of  the  tendons  of  the 
flexor  j>i-i>fini<ltix  ilif/itni'iiiii,  the  outermost  (for  the  index  linger)  is  separated  from  the 
others:  the  remaining  three  are  in  close  contact  until  after  they  enter  the  palm. 
I'lach  flexor  snblimis  tendon  is  accompanied  to  the  root  of  its  respective  linger 
by  the  corresponding  deep  flexor  tendon  which  lies  under  it.  The  tendons  of 
the  deep  flexov  give  origin  to  the  Inmbrical  muscles.  The  flexor  tendons  are 
confined  to  the  phalanges  by  fibrous  sheaths,  which  must  lie  laid  open  in  order 
to  expose  the  tendon. 

The  li/irniix  .s7/m///.s  of  the  flexor  tendons  are  subcutaneous.  I'] ion  either 
side  of  these  sheaths  are  the  collateral  digital  vessels  and  nerves.  The  sheaths 
are  attached  to  the  sharp  lateral  margins  of  the  anterior  surface"  of  the  phalanges, 
and  thus  form  an  osteo-fibnuis  canal,  which  is  composed  of  bone  behind  and 
fibrous  tissue  in  front.  The  sheaths  are  thin  ut  the  joints  and  thick  opposite 
tin'  body  of  the  phalanges,  and  especially  so  opposite  the  middle  of  the  proximal 
phalanges,  at  which  point  they  are  called  the  rftf/!i«il  tii/tniirnt.  Throughout  its 
entire  length,  each  fibrous  sheath  is  lined  by  a.  synovial  membrane,  which  is 
reflected  over  the  tendons,  thus  forming  a  tubular  sac,  or  fln-cft.  The  theca', 
or  synovial  sacs,  of  the  index,  middle,  and  ring  fingers  extend  from  the 


ANATOMY. 

heads  of  the  metacarpal  bones  to  the  middle'  of  the  distal  phalanges,  and 
do  not  communicate  \vitli  the  carpal  bursa'.  while  those  of  the  thuml)  and 
little  linger  do. 

Upon  the  undei-  surface  of  the  llexor  tendons,  as  they  pass  along  tin1  tinkers, 
synovial  relleetions  are  found  connecting  them  with  the  adjacent  bone.  These 
are  triangular  near  the  insertion  of  the  tendon,  and  are  called  lit/aim  uln  ln-crin  : 
longer  and  slender  relleetions,  called  lii/nmt  nt<i  /"/'.'/".  make  similar  connections, 
but  further  from  the  insertion  of  the  tendon,  both  being  known  collectively  as 
the  trincula  aecessoria.  These'  vinciila  carry  lilood-vessels  to  the  llexor  tendons. 
Inflammation  of  the  thecse  is  known  as  thecitis.  If  the  inflammation  results 
in  a  purulent  collection  within  the  theea.  it  constitutes  a  superficial  felon; 
while  if  the  pus  forms  beneath  the  periostea!  covering  of  the  phalanx,  a  dee])  felon 
results.  Superficial  felons  should  be  incised  in  the  median  line  of  the  finger, 
SO  as  to  avoid  the  collateral  digital  arteries;  wbile  deep  felons  are  preferably 
opened  by  an  incision  made  along  the  side  of  the  tendon. 

The  iiixfriiniix  of  the  flexor  tendons  are  as  follows:  Each  tendon  of  the  llexor 
sublimis  digitorum  rests  upon  the  corresponding  tendon  of  the  llexor  profundns 
digitorum  ;  opposite  the  metacarpo-phalangeal  joints  the  tendons  of  the  flexor  sub- 
limis broaden  and,  opposite  the  middle  of  the  proximal  phalanges,  split  into  two 
segments,  between  which  pass  the  tendons  of  the  flexor  profundns  ;  they  reunite 
and  again  divide,  to  bo  inserted  into  the  middle  of  both  sides  of  the  second  pha- 
langes :  the  tendon  of  the  flexor  profundus,  after  perforating  the  tendons  of  the 
flexor  sublimis,  passes  on  for  insertion  into  the  front  of  the  base  of  the  last 
phalanx  ;  the  tendon  of  the  flexor  longus  pollicis  passes  between  the  two  heads 
of  the  llexor  brevis  pollicis  for  insertion  into  the  front  of  the  base  of  the  last 
phalanx  of  the  thuml). 

The  lumbricales  are  four  slender,  fleshy  muscles  which  are  accessory  to  the 
deep  flexor  tendons  and  connect  these  with  the  tendons  of  the  extensor  communis 
digitorum.  They  arise  from  the  radial  side  of  the  deep  flexor  tendons  of  the  index 
and  middle  fingers,  and  from  the  adjacent  sides  of  the  tendons  of  the  middle,  ring, 
and  little  fingers.  Each  muscle  terminates  in  a  delicate  tendon,  which  passes 
around  the  radial  side  of  the  base  of  the  proximal  phalanx  of  the  corresponding 
finger  and  is  inserted  into  the  tendon  of  the  extensor  communis  digitorum  upon 
flie  back  of  the  proximal  phalanx. 

BLOOD  SUPPLY. — From  the  digital  branches  of  the  superficial  palmar  arch  and 
the  interosseous  branches  of  the  deep  palmar  arch. 

NERVE  SUPPLY. — The  outer  two  lumbrical  muscles  arc  supplied  by  branches 
of  the  median  nerve,  and  the  inner  two  by  the  ulnar  nerve. 

ACTION. — These    muscles   aid  the  flexor    tendons    in   flexing  the    metacarpo- 


PLATE  XLVI. 


-Flexor prof undus  digtforum  fendon. 


-Flexor  sublimis  digitorum  tendon. 


Common  extensor  tendon- 4 


/rUer-osscous  m. 


Mefo-carpat  done  -  - 


Ltunvrical  m. 


INSERTION  OF  LUMBRICAL  AND   INTEROSSEOUS  MUSCLES. 
169 


'/'///•;  I-'I;O\T  OF  TIH-:  IIAXD.  1:1 

phalangeal  joints  and  the  extensor  tendons  in  extending  the  two  interphalangeal 
joints. 

DISSECTION. —  Kemove  the  lateral  portions  of  the  deep  palmar  fascia  and 
separate  the  muscles,  of  the  thenar  and  livpotheiiar  eminences. 

The  thenar  eminence,  or  hall  of  the  thumh.  is  composed  of  four  muscles, 
called  the  abductor  pollicis,  opponens  pollicis,  ilexor  brevis  jiollicis,  and  adductor 
pollicis. 

The  abductor  pollicis,  the  most  superficial  muscle  of  the  ball  of  the  thumb,  is 
ii  ihin.  Hat  muscle  which  arises  from  the  front  of  the  anterior  annular  ligament  and 
the  trapezium.  It  is  inserted  into  the  radial  side  of  the  base  of  the  first  phalanx  of 
the  thumb  and  the  tendon  of  the;  extensor  secnndi  internodii  pollicis  over  the  first 
phalanx.  It  rests  upon  the  opponens  pollicis  and  the  superficial  or  outer  head  of 
the  flexor  brevis  pollicis. 

lli.ooii  SriTLY. — From  the  superficialis  vohe  arterv. 

\KI;VK  Sri'i-LY. — From  the  median  nerve. 

ACTION. — It  abducts  the  thumb  and  assists  in  extension  of  the  last  phalanx. 

I)ISSK<TK>\. — Cut  the  muscle  transversely  at  its  middle,  and  reflect. 

The  opponens  pollicis  is  small  and  triangular,  and  is  subcutaneous  in  its  outer 
part,  while  its  inner  portion  is  covered  by  the  abductor  pollicis.  It  arises,  beneaili 
the  abductor,  from  the  front  of  the  anterior  annular  ligament  and  the  trapezium, 
whence  its  fibers  diverge  for  insertion  into  the  radial  side  of  the  entire  length  of 
the  mctacarpal  bone  of  the  thumb.  It  is  covered  by  the  abductor  pollicis  and  the 
deep  fascia.  It  lies  upon  the  joint  between  the  trapezium  and  the  metacarpal  bone 
of  the  thumb  and  on  the  radial  side  of  the  superficial  or  outer  head  of  the  flexor 
brevis  pollicis. 

I'.i.oon  SriTLY. — From  the  radial  and  superficial  volar  arteries. 

XKUVK  SriTLY. — From  the  median  nerve.. 

ACTION. — It  draws  the  head  of  the  metacarpal  bone  of  the  thumb  toward  the 
head  of  the  metacarpal  bone  of  the  little  finger,  after  which  contraction  of  tin- 
long  and  short  flexors  brings  the  end  of  the  thumb  in  contact  with  the  base  of 
the  little  finger. 

The  flexor  brevis  pollicis  arises  by  a  superficial  and  a  deep  head,  between 
which  passes  the  tendon  of  the  flexor  longus  pollicis.  The  aujH'i-Jii-inl  //'</</ arises 
from  the  outer  part  of  the  anterior  annular  ligament  and  the  trapc/ium  ;  the  i/ir/i 
IK-HI/  (by  some  described  as  a  separate  muscle,  and  called  the  oblique  adductor  of 
the  thumb)  arises  from  the  bases  of  the  first,  second,  and  third  mctacarpal  bones, 
from  the  trapezoid  and  os  magnum,  and  the  sheath  of  the  tendon  of  the  flexor 
carpi  radialis.  The  fibers  from  these  origins  unite  and  then  separate  for  insertion 
into  both  the  outer  and  inner  side  of  the  base  of  the  first  phalanx  of  the  thumb. 


172  SURGICAL    .I.V.I  To  MY. 

Kadi  tendon  of  insertion  contains  a  scsainoid  bofle  where  it  passes  over  the  ineta- 
Carpo-phalangeal  joint  ;  the  tendon  of  tlie  Miperlicial  or  outer  head  is  joined  by  tlie 
tendon  of  tlie  abductor  pollicis,  and  that  of  tlie  deep  or  inner  head  by  tlie  tendon  of 
tlie  adductor  pollicis.  The  superficial  or  outer  head  lies  in  contact  with  the  ulnar 
border  of  the  opponens  pollicis,  and  is  coyci-cil  by  the  abductor  pollicis  and  the 
deep  fascia.  It  rests  upon  the  opponens  pollicis,  the  tendon  of  tlie  flexor  longus 
pollicis,  and  the  inner  or  deep  head.  The  superficial  or  outer  head  is  covered  by 
the  deep  fascia;  the  deep  or  inner  head  by  the  llexor  tendons  of  the  index  and 
middle  lingers  and  the  outer  two  luinbrieales.  It  rests  upon  the  deep  palmar 
arch,  the  muscles  of  the  first  two  interosseous  spaces,  the  tendon  of  the  flexor  carpi 
radialis,  and  the  radialis  indicis  artery. 

BLOOD  SUPPLY. — From  the  radial  artery. 

NERVE  SUPPLY. — From  the  median  nerve,  and  the  deep  branch  of  the  ulnar 
nerve.  The  median  nerve  supplies  the  superficial  or  outer  head,  the  deep  branch 
of  the  ulnar  nerve  the  deep  or  inner  head. 

ACTION. — It  ilexes  the  carpo-metacarpal  and  metacarpo-phalangeal  joints  of 
the  thumb.  Tlie  deep  or  inner  head  is  also  an  oblique  adductor,  aiding  the 
contiguous  adductor  pollicis  in  drawing  the  head  of  the  metacarpal  bone  of  the 
thumb  toward  the  pisiform  bone. 

The  adductor  pollicis  is  the  deepest  muscle  of  this  group,  and  is  triangular 
in  .shape.  It  arises  by  its  base  from  the  front  of  the  metacarpal  bone  of  the 
middle  finger,  whence  its  fibers  converge  for  insertion  into  the  ulnar  side  of  the 
base  of  the  first  phalanx  of  the  thumb,  in  common  with  the  inner  tendon  of  the 
tlexor  brevis  pollicis.  It  is  covered  by  the  ulnar  border  of  the  deep  or  inner  bend 
of  the  flexor  brevis  pollicis,  the  outer  two  tendons  of  the  flexor  sublimis  and 
flexor  profundus  digitorum  muscles,  and  the  two  outer  luinbrieales.  It  lies  upon 
the  radialis  indicis  artery,  the  abductor  indicis  muscle,  and  the  interosseous  muscles' 
of  the  second  interosseous  space. 

BLOOD  SUPPLY. — From  branches  from  both  palmar  arches. 

NERVE  SUPPLY. — From  the  deep  branch  of  the  ulnar  nerve. 

ACTION. — It  adducts  the  thumb,  approximating  it  to  the  index  linger. 

The  hypothenar  eminence  is  the  fleshy  prominence  upon  the  inner  side  of 
the  palm  of  the  hand.  It  is  composed  of  the  palmaris  brevis,  the  abductor 
minimi  digiti,  the  flexor  brevis  minimi  digiti,  and  the  opponens  minimi  digiti  :  the 
last  three  are  the  short  muscles  of  the  little  finger.  The  palmaris  brevis  has 
already  been  described. 

The  abductor  minimi  digiti  lies  upon  the  ulnar  side  of  the  hypothenar  emi- 
nence, and  arises  from  the  pisiform  bone  and  an  expansion  of  the  tendon  of  the 
flexor  carpi  ulnaris.  It  is  inserted  by  a  flattened  tendon  into  the  ulnar  side  of  the 


PLATE  XLVII 


Radial  a. 

Flexor  longus  pollicus  tend 

Anterior  carpal  a. 

Supetficlalis  voUe  a, 
Flexor  carpi  radiai;s  tendon 


Anterior  carpal  arch 


Anterior  annular  ligament  (cut  edges) 


Recurrent  carpal  a, 

Flexor  brevis  minimi  digiti  m.(cut) 


Princeps  poilicis  a. 
Perforating  a. 

Radial  is  indicis  a. 


Abductor  indicis  or  first 
dorsal  mterosseous  m 


pi  ulnarii 
or  caipal  a. 


Deep  palmar  arch 
s  irinimi  digiti  m, 


Tendon  of  flexor  sublimis  digitorum 


Collateral  digital  a. 


Tendon  of  flexor  orofundus  digitorum  — 


DEEP  PALMAR  ARCH  AND   INTEROSSEOUS  MUSCLES. 
173 


PLATE  XLVIII. 


Radial  a. 


Superficial  volae  a. 


Princeps  pollicis  a. 


Radialis  indicis  a 


Digital  a.. 


Interosseous  a._ 


Ulnar  a. 


Deep  branch  of  ulnar  a. 


Deep  palmar  arch 
for  deep  palmar  arch 

Superficial  palmar  arch 

Line  for  superficial 
palmar  arch 


PALM  OF 


,- LINES  OF  ARTERIES. 
176 


PLATE  XLIX, 


Anterior  interosseous  a. 

Dinar  a. 
Anterior  carpal  a. 

Posterior  carpal  a. 


.Anterior  branch  of  anterior 
interosseous  a. 

Anterior  carpal  a. 


Deep  branch  of  ulnar  a. 

Perforating  a. 
Palmar  interosseous  a. 
Dorsal  interosseous  a. 

Perforating  a. 
Collateral  digital  a 


Superficial  volae  a. 
Radial  a. 


Posterior  carpal  a. 

Dorsalis  poliicis  a. 

A Recurrent  carpal  a. 

Deep  palmar  arch 

Dorsalis  indicis  a. 
Princeps  poliicis  a. 

Superficial  palmar  arch 
Radialis  indicis  a. 
Digital  a. 


ARTERIES  OF  HAND, 
177 


THE  FRONT  OF  THE  HAM).  179 

base  of  the  first  phalanx  of  the  little  finger  and  into  the  same  side  of  the  tendon 
of  the  extensor  minimi  digit i.  It  is  subcutaneous,  exeept  at  its  base,  where  it  is 
covered  by  the  palmaris  brevis.  It  rests  upon  the  opponens  minimi  digiti  on  the 
ulnar  side  of  the  flexor  brevis  minimi  digiti. 

BLOOD  SUPPLY. — From  the  ulnar  artery. 

NERVE  SUPPLY. — From  the  deep  branch  of  the  ulnar  nerve. 

ACTION. — It  abducts  the  little  finger,  flexes  the  metacarpophalangeal  articula- 
tion, and  extends  the  interphalangeal  joints  of  that  finger. 

The  flexor  brevis  minimi  digiti  lies  upon  the  radial  side  of  the  preced- 
ing muscle  and  arises  from  the  anterior  annular  ligament  and  the  hook  of 
the  unciform  bone.  It  is  inserted,  with  the  preceding  muscle,  into  the  ulnar 
side  of  the  base  of  the  proximal  phalanx  of  the  little  finger.  It  is  subcuta- 
neous, except  where  it  is  covered  by  the  palmaris  brevis.  It  rests  upon  the 
opponens  minimi  digiti. 

BLOOD  SUPPLY. — .From  the  ulnar  artery. 

NERVE  SUPPLY. — From  the  deep  branch  of  the  ulnar  nerve. 

ACTION. — It  flexes  the  metacarpo-phalangeal  joint  of  the  little  finger. 

The  opponens  minimi  digiti  (also  called  flexor  ossis  metacarpi  minimi  digiti), 
is  triangular  in  form  and  corresponds  to  the  opponens  pollicis.  It  arises  at  its 
apex  from  the  anterior  annular  ligament  and  the  hook  of  the  unciform  bone, 
whence  its  fibers  diverge  for  insertion  into  the  entire  length  of  the  ulnar  margin 
of  the  metacarpal  bone  of  the  little  finger.  It  is  covered  by  the  two  preceding 
muscles,  and  rests  upon  the  interosseous  muscles  of  the  fourth  interspace,  the 
metacarpal  bone,  and  the  deep  branches  of  the  ulnar  artery  and  nerve. 

BLOOD  SUPPLY. — From  the  ulnar  artery. 

NERVE  SUPPLY. — From  the  deep  branch  of  the  ulnar  nerve. 

ACTION. — It  draws  the  head  of  the  metacarpal  bone  of  the  little  finger  forward 
and  toward  the  radial  side  of  the  hand,  aiding  in  hollowing  the  palm  and  in 
approximating  the  little  finger  to  the  thumb. 

DISSECTION. — Divide  the  anterior  annular  ligament  and  the  flexor  tendons  ; 
reflect  the  latter,  with  the  lumbrical  muscles,  downward,  when  the  deep  transverse 
laver  of  fascia  which  covers  the  deep  palmar  arch,  the  deep  branch  of  the  ulnar 
nerve,  the  interossei  muscles,  and  the  metacarpal  bones  will  be  exposed.  Remove 
the  deep  transverse  layer  of  fascia  and  trace  the  vessels  and  nerve  beneath  it. 
Next,  sever  the  adductor  pollicis  and  inner  or  deep  head  of  the  flexor  brevis 
pollicis  at  their  origins,  and  reflect  them  in  order  to  expose  the  remainder  of  the 
deep  palmar  arch  and  the  origins  of  the  princeps  pollicis  and  radialis  indicis 
arteries. 

The  deep  palmar  arch  is  the  terminal  portion  of  the  radial  artery.     It  begins 


180  SURGICAL   A \.\TO.MY. 

at  the  entrance  of  the  radial  artery  into  the  palm,  between  the  two  heads  of  the 
first  dorsal  interosseous  (abductor  indicis)  muscle.  It  then  passes  between  the 
adductor  pollicis  and  the  inner  head  of  the  Hexor  lirevis  pollieis,  whence  it  arches, 
convexity  downward,  over  the  bases  of  the  metacarpal  hones  and  the  ])almar  inler- 
osseoiis  muscles  to  the  base  of  the  metacarpal  bone  of  the  little  finger,  where  it  is 
completed  by  joining  the  deep  branch  of  the  ulnar  artery.  It  is  less  curved  than 
the  superficial  arch  and  is  situated  one-half  of  an  inch  nearer  the  wrist.  It  is 
accompanied  by  the  deep  branch  of  the  ulnar  nerve. 

The  In-ii iirlics  of  the  deep  palmar  arch  are,  from  its  convexity,  the  princrps 
pollicis,  the  radialis  indicis,  the  palmar  interosseous,  and  the  superior  perforating, 
and,  from  the  concavity  of  the  arch,  the  recurrent  carpal  arteries. 

The  princeps  pollicis  artery  arises  separately  or  by  a  common  trunk  with  the 
radialis  indicis  from  the  arch,  close  to  the  interval  between  the  two  heads  of  the 
first  dorsal  interosseous  muscle.  It  first  passes  between  the  first  dorsal  interosseous 
muscle  and  the  flexor  brevis  pollicis,  then  between  the  two  heads  of  the  latter  along 
the  metacarpal  bone  of  the  thumb,  under  cover  of  the  tendon  of  the  flexor  longus 
pollicis,  to  the  base  of  the  first  phalanx,  where  it  divides  into  two  collateral 
branches  which  descend  upon  the  sides  of  the  thumb,  with  the  tendon  of  the  flexor 
longus  pollicis  between  them.  They  terminate  in  an  arch  similar  to  that  formed 
by  the  collateral  arteries  of  the  fingers. 

The  radialis  indicis  artery  is  given  off  near  the  preceding  artery.  It  passes 
between  the  first  dorsal  interosseous  muscle  (abductor  indicis)  and  the  adductor 
pollicis  along  the  palmar  aspect  of  the  radial  border  of  the  index  finger. 

The  palmar  interosseous  arteries,  three  in  number,  pass  downward  over  the 
interosseous  muscles  in  the  second,  third,  and  fourth  interosseous  spaces,  to  join  the 
corresponding  digital  branches  of  the  superficial  palmar  arch  just  before  they  divide 
into  the  collateral  digital  arteries. 

The  superior  perforating  arteries,  three  in  number,  pierce  the  upper  ends  of 
the  inner  three  interosseous  spaces,  and  pass  between  the  heads  of  the  dorsal  inter- 
osseous muscles  to  join  the  dorsal  interosseous  arteries. 

The  recurrent  carpal  arteries,  two  or  three  in  number,  pass  upward,  in  front 
of  the  wrist,  to  join  branches  of  the  anterior  carpal  arch  and  the  anterior  branch 
of  the  anterior  interosseous  artery. 

When  one  of  the  palmar  arches  is  .wounded,  control  the  hemorrhage  by 
making  pressure  upon  the  radial  and  ulnar  arteries,  and  cleanse  the  wound.  The 
artery  should  be  completely  severed,  for  a  partially  divided  artery  presents  a 
gaping  wound  ;  contraction  and  retraction  of  the  cut  ends  are  thus  prevented. 
If  it  be  possible  without  making  a  large  wound,  tie  both  bleeding  ends  in  the 
wound.  A  large  scar  in  the  palm  is  a  source  of  danger,  because  constant 


PLATE  L. 


Supra  acromial  n 


Cutaneous  branch  of  circumflex  n.. 
Intercosto-humeral  n. 


Branch  of  internal  cutaneous  n 


Lesser  internal  cutaneous  n 


Internal  cutaneous  n, 

External  cutaneous  branch  of 

musculo-spiral  n. 


M  jsculo-cutaneous  n. 


Palmar  cutaneous  branch  of  ulnar  n. 
Palmar  cutaneous  branch  of  radial  n 
Palmar  cutaneous  branch  of  median 


Supra  acromial  n. 


_Branch  of  circumflex  n. 


..Internal  cutaneous  branch  of 
musculo-spiral  n. 

_lntercosto-humeral  n. 


.  Branch  of  circumflex  n. 


-Lesser  internal  cutaneous  n. 


Branch  of  internal  cutaneous  n. 
ternal  cutaneous  of  musculo-spiral  n. 


Branch  of  musculo-cutaneous  n. 


_  Radial  n  • 

_ Dorsal  cutaneous  branch  of  ulnar  n. 


CUTANEOUS  NERVES  OF  ARM  AND  FOREARM, 
181 


PLATE  LI. 


Spine  of  scapula 

_Supraspinatus  m. 
Infraspinatus  m. 

Teres  minor  m. 


Teres  major  in.. 


Long  head  of  triceps  m 


Musculo-spiral  n. 


Superior  profunda  a. 
Inner  head  of  triceps  m 


Triceps  tendon. 


Anconeus  rp.- 


Circumflex  n. 
Posterior  circumflex  a. 


Outer  head  of  triceps  m. 


Deltoid  in. 


Brachialis  anticus  m. 


Supinator  longus  rr1i 


Extensor  carpi  radialis  longior  m. 


Extensor  carpi  radialis  brevior  m. 
Extensor  communis  digitorum  m. 


MUSCULO-SPIRAL  NERVE  AND  SUPERIOR  PROFUNDA  ARTERY. 
184 


PLATE  LI  I. 


Teres  major  m 

Branch  of  dorsalis  scapulae  a. 

Latissimus  dorsi  tendon 


Dinar  n 


Flexor  carpi  ulnaris  m.- 


Supraspinatus  m. 


—  Infraspinatus  m. 

Greater  tuberosity  of  humerus 
Teres  minor  m. 


Circumflex  n. 


Posterior  circumflex  a 


Long  head  of  triceps  m. 


Outer  head  of  triceps  m 


Tendon  of  triceps  m. 


MUSCLES  OF  THE  BACK  OF  THE  SCAPULA  AND  ARM. 
185 


THE  FRONT  OF  THE  HAND.  187 

irritation  may  develop  an  epithelioma.  If  ligature  of  the  bleeding  ends  be 
not  possible,  use  a  graduated  compress.  This  may  be  made  by  placing  a 
small  piece  of  dry  antiseptic  gauze  or  lint  upon  the  bleeding  points  in  the  bottom 
of  the  wound  and  then  adding  successively  larger  sections  of  dry  gauze  or  lint. 
The  metacarpal  bones  supply  the  requisite  counterpressure.  The  compress  is 
covered  with  aseptic  cotton  and  a  bandage  applied.  The  amount  of  pressure 
required  is  very  small.  The  dressing  is  removed  after  twelve  hours.  If  this 
method  does  not  succeed,  forcipressure  may  be  used — hemostatic  forceps  are  allowed 
to  remain  attached  to  the  bleeding  arteries.  Flexion  of  the  elbow  and  wrist  should 
also  be  practised  in  conjunction  with  the  compress  and  forcipressure.  If  these 
means  fail,  the  brachial  should  be  tied  above  the  bend  of  the  elbow.  If  the  radial 
and  ulnar  are  ligatured,  hemorrhage  from  a  wounded  superficial  palmar  arch  may 
still  occur  through  a  large  median  artery ;  and,  from  a  wounded  deep  palmar  arch, 
through  a  large  anterior  inter  osseous  artery.  Both  of  these  possibilities  are 
eliminated  by  ligature  of  the  brachial  artery. 

The  palmar  interossei  are  three  slender  muscles,  the  first  of  which  arises 
from  the  ulnar  side  of  the  metacarpal  bone  of  the  index  finger  and  is  inserted  into 
the  base  of  the  first  phalanx  and  the  extensor  tendon  of  the  same  finger ;  the  sec- 
»ii(l  from  the  radial  side  of  the  metacarpal  bone  of  the  ring  finger,  and  is  inserted 
into  the  base  of  the  first  phalanx  and  the  extensor  tendon  upon  the  same  side  of 
this  finger ;  the  third  has  a  similar  origin,  and  insertion  upon  the  radial  side  of  the 
little  finger. 

BLOOD  SUPPLY. — These  muscles  are  nourished  by  the  deep  palmar  arch. 

NERVE  SUPPLY. — From  the  deep  branch  of  the  ulnar  nerve. 

ACTION. — They  adduct  the  fingers  to  which  they  are  attached,  flex  the  respec- 
tive metacarpo-phalangeal  joints,  and  extend  the  last  two  phalanges.  By  adduc- 
tion of  the  fingers  is  meant  drawing  them  toward  the  median  line  of  the  middle 
finger,  while  abduction  is  drawing  the  fingers  away  from  that  line. 


The  muscles  of  the  upper  extremity  which  are  seen  in  dissecting  the  back  are 
described  under  the  dissection  of  the  back  of  the  neck,  shoulder,  and  back.  These 
muscles  are  the  trapezius,  rhomboidei,  latissimus  dorsi,  supra-spinatus,  infra- 
spinatus,  teres  major,  teres  minor,  subscapularis,  and  serratus  magnus. 


188  tntGICAL  ANATOMY. 

THE  BACK  or  Till-:  ARM. 

DISSECTION. — With  the  body  lying  face  downward,  abduct  the  arm  In  a  right 
angle  with  tin-  trunk.  If  the  body  lie  upon  its  back,  ilex  the  forearm  upon  the 
arm  and  addurt  the  arm  across  the  upper  part  of  the  chest  so  that  the  elbow  will 
be  opposite  the  nock.  Fix  the  arm  in  this  position  by  means  of  hooks.  Continue 
the  transverse  incision,  made  on  the  upper  part  of  the  front  of  the  forearm,  around 
the  back  of  the  forearm,  and  reflect  the  skin  toward  the  shoulder.  In  removing 
the  superficial  fascia,  which  is  best  done  from  without  inward,  trace  the  superficial 
nerves  when  reflecting  the  fascia.  The  nerves  which  supply  the  skin  and  super- 
ficial fascia  of  the  back  of  the  arm  are,  from  without  inward,  the  inferior  external 
cutaneous  branch  of  the  musculo-spiral,  the  terminal  portion  of  the  lower  branch 
of  the  circumflex,  the  intercosto-humeral,  the  lesser  internal  cutaneous,  and  the 
internal  cutaneous  of  the  musculo-spiral. 

Before  dissecting  out  the  superficial  nerves,  note  the  bursa  found  over  the 
olecranon.  It  is  generally  of  considerable  size,  and  may  be  very  prominent  if 
distended,  constituting  what  is  known  as  "miner's  elbow."  Other  bursre  may 
sometimes  be  found  over  the  internal  and  external  condyles  of  the  humerus,  and, 
lower  down,  upon  the  ulna  and  over  its  styloid  process. 

The  inferior  external  cutaneous  branch  of  the  musculo-spiral  nerve  becomes 
superficial  upon  the  outer  side  of  the  arm  below  the  insertion  of  the  deltoid,  and 
then  passes  backward  and  downward  behind  the  outer  humeral  condyle  to  the 
forearm.  The  terminal  portion  of  the  lower  branch  of  the  circumflex  nerve  pierces 
the  deep  fascia,  and  supplies  the  skin  over  the  lower  part  of  the  posterior  surface 
of  the  deltoid  muscle  and  the  long  head  of  the  triceps. 

The  internal  cutaneous  branch  of  the  musculo-spiral  nerve  emerges  from  the 
axilla  at  the  outer  end  of  the  posterior  fold,  and  passes  downward  along  the  inner 
and  back  part  of  the  arm  toward  the  elbow. 

The  intercosto-humeral  nerve  passes  down  the  arm,  upon  the  inner  side  of 
the  internal  cutaneous  branch  of  the  musculo-spiral  nerve,  to  supply  the  skin  of 
the  inner  and  back  part  of  the  arm. 

The  lesser  internal  cutaneous  nerve  turns  toward  the  back  of  the  arm,  above 
the  internal  condyle,  descending  to  the  inner  side  of  the  olecranon. 

Deep  fascia. — Next  remove  the  deep  fascia  in  the  same  manner  as  the  super- 
ficial fascia.  The  deep  fascia  on  the  back  of  the  arm  is  the  continuation  of  that 
covering  the  front  of  the  arm.  It  is  closely  attached  to  the  tendon  of  the  triceps 
and  the  bony  prominences  of  the  elbow. 

The  Triceps  is  the  only  muscle  on  the  back  of  the  arm.  It  arises  from  the 
scapula  and  the  back  of  the  shaft  of  the  humerus.  The  origin  from  the  latter 


PLATE  till, 


Posterior  ulnar  v. 


Communication  with  deep  veins 


Deep  fascia 


Radial 


SUPERFICIAL  VEINS  OF  BACK  OF  FOREARM  AND  HAND. 
190 


THE   HACK  OF  THE  AR.M.  I'-'l 

bone  is  divided  into  two  portions,  by  the  musculo-spiral  groove  which  passes 
obliqui-ly  downward  and  from  within  outward.  The  portion  of  the  muscle  which 
arises  from  the  scapula  is  called  the  lour;  l/nnl,  and  that  from  above  and  external 
to  the  musculo-spiral  groove  of  the  humerns,  the  external  land;  while  that  below 
and  internal  to  the  groove,  the  internal  lanl. 

The  long,  middle,  or  scapular  head  arises  by  a  flat  tendon  from  a  triangular 
depression  on  the  axillary  border  of  the  scapula,  immediately  below  the  gleimid 
cavity  ;  it  blends  with  the  glenoid  and  capsular  ligaments,  the  long  head  of  the 
biceps  being  similarly  attached  at  the  upper  margin  of  the  same  cavity. 

The  external  head  arises  from  the  posterior  surface  of  the  shaft  of  the 
humerus,  above  and  external  to  the  musculo-spiral  groove,  and  from  the  external 
intermuscular  septum  to  the  point  where  it  is  pierced  by  the  musculo-spiral  nerve. 
The  surface  of  origin  extends  as  high  as  the  insertion  of  the  teres  minor. 

The  inner  or  short  head  arises  from  the  back  of  the  shaft  of  the  humerus 
below  and  internal  to  the  musculo-spiral  groove,  the  internal  intermuscular  septum 
and  the  external  intermuscular  septum  below  the  point  where  it  is  pierced  by  the 
musculo-spiral  nerve.  The  surface  of  origin  extends  upward  as  far  as  the  insertion 
of  the  teres  major  into  the  posterior  bicipital  ridge  and  downward  to  within  one- 
half  of  an  inch  of  the  upper  edge  of  the  olecranon  fossa. 

Tendon  of  insertion. — The  long  head  becomes  tendinous  in  the  lower  third  of 
the  arm  where  it  is  joined  on  the  outer  side  by  the  external  head.  The  greater 
part  of  the  internal  head  is  attached  to  the  under  surface  and  either  side  of  this 
tendon.  The  deeper  fibers  of  the  internal  head  are  inserted  directly  into  the 
olecranon  and  posterior  ligament  of  the  elbow-joint.  The  common  tendon,  which 
is  inserted  into  the  summit  and  sides  of  the  olecranon,  is  continuous  with  the 
deep  fascia  of  the  forearm  upon  either  side. 

The  long  head  of  the  triceps,  in  its  descent  from  the  scapula,  passes  between 
the  teres  minor  behind  and  the  teres  major  in  front,  and  assists  in  forming  a  quad- 
rangle which  is  bounded  by  the  humerus  externally,  the  teres  minor  above,  the 
long  head  of  the  triceps  internally,  and  the  teres  major  below  ;  a  triangle  is  found 
just  below,  bounded  above  by  the  teres  minor  and  subscapularis,  below  by  the  teres 
major,  and  externally  by  the  long  head  of  the  triceps.  The  quadrangle  transmits 
the  posterior  circumflex  vessels  and  the  circumflex  nerve,  and  the  triangle  the 
dorsalis  scapulae  vessels. 

The  posterior  surface  of  the  triceps  is  subcutaneous,  except  at  its  upper  end, 
where  it  is  covered  by  the  deltoid.  The  anterior  surface  is  in  relation  with  the 
humerus,  the  musculo-spiral  nerve,  the  superior  profunda  vessels,  and  the  elbow- 
joint.  The  long  head  lies  in  front  of  the  deltoid  and  teres  minor,  and  behind  the 
subscapularis,  latissimus  dorsi,  and  teres  major  muscles. 


I'.i-J  SURGICAL  ANATOMY. 

BLOOD  Srrri.v. — The  nutriment  of  the  triceps  is  derived  from  the  superior 
and  inferior  profunda.,  the  iiimsiuiiKitieu  magna,  and  muscular  branches  of  the 
hrachial  artery. 

XKKVK  Srrri.Y.— From  the  imisculn-spiral  nerve. 

ACTION. — It  extends  the  forearm  and  adducts  t  lie  hunierus.  The  long  head, 
by  preventing  downward  luxation  of  the  head  of  the  humcrus,  forms  a  protection 
to  the  shoulder-joint. 

The  subanconeus  is  a  very  small  muscle  bearing  the  same  relation  to  the 
triceps  muscle  and  the  elbow-joint  that  the  subcrureus  does  to  the  crureus  muscle 
and  the  knee-joint.  It  consists  of  those  fibers  of  the  internal  head  of  the  triceps 
which  are  inserted  into  the  posterior  ligament  of  the  elbow-joint. 

NERVE  SUPPLY. — The  same  as  that  of  the  triceps. 

ACTION. — It  draws  the  posterior  ligament  upward  during  the  relaxation 
accompanying  extension  of  the  elbow  and  prevents  pinching  of  the  synovial 
membrane. 

The  musculo-spiral  nerve  is  best  observed  on  the  back  of  the  arm,  after 
division  of  the  long  and  external  heads  of  the  triceps  muscle  over  the  musculo- 
spiral  groove,  when  the  branches  given  off  to  the  triceps  can  be  traced.  From  the 
branch  to  the  internal  head  a  small  nerve,  accompanied  by  the  posterior  articular 
branch  from  the  superior  profunda  artery,  may  be  seen  passing  downward  under 
cover  of  the  outer  edge  of  the  tendon,  from  beneath  which  it  emerges  between 
the  oltrraiion  and  external  condyle  of  the  humerus  to  enter  and  supply  the  anco- 
neus  muscle.  Owing  to  its  proximity  to  the  bone,  the  musculo-spiral  nerve  may 
be  injured  in  fractures,  or  become  involved  in  the  resulting  callus. 

The  superior  profunda  artery,  lying  in  the  groove  with  the  musculo-spiral 
nerve,  is  exposed  by  the  same  dissection.  As  it  emerges  from  under  the  outer  edge 
of  the  triceps  it  sends  off  a  large  superficial  branch  (posterior  articular)  to  the 
elbow,  after  which  it  divides  into  two  branches,  one  passing  between  the  triceps 
and  the  bone  to  anastomose  with  the  interosseous  recurrent  and  anastomotica 
magna  arteries,  the  other  extending  downward,  between  the  supinator  longus  and 
the  brachialis  anticus,  to  join  the  radial  recurrent  artery. 


13 


PLATE 


Triceps  tendon 


Ulnar  n 


Flexor  carpi  ulnaris  m. 


Extensor  minimi  digiti  m. 


Extensor  carpi  ulnaris  m. 


Posterior  interosseous  a. 


Posterior  carpal  arch 


Biceps  m. 

Brachialis  anticus  m. 
Supinator  longus  m. 
Superior  profunda  a. 


Anconeus  m. 

Extensor  carpi  radialis  longior  m. 

Extensor  carpi  radialis  brevier  m. 
Extensor  cotnmunis  digitorum  m. 


Extensor  ossis  rnetacarpi  pollicis  m. 
Extensor  primi  internodii  pollicis  m. 

Extensor  secundi  internodii  pollicis  m. 
Extensor  carpi  radialis  brevior  tendon 
Posterior  annular  ligament 

Extensor  carpi  radialis  longior  tendon 
Radial  a. 


SUPERFICIAL  MUSCLES  OF  BACK  OF  FOREARM, 
194 


THE  BACK  OF   THE  FOREARM.  195 

THE  BACK  OF  THE  FO I II-:.  HIM. 

DISSECTION. — Reflect  the  skin  from  the  hack  of  the  forearm  and  hand  as  far  as 
the  roots  of  the  fingers,  and  sever  it  at  this  point.  Next  incise  the  skin  of  the 
fingers  in  the  median  line  and  reflect  it  laterally.  By  reflecting  the  skin  of  the 
dorsum  of  the  hand  and  fingers  at  the  same  time,  a  better  opportunity  is  given  for 
studying  the  superficial  .structures.  The  superficial  fascia  is  now  exposed.  It 
contains  the  superficial  veins,  lymphatics,  and  nerves. 

Tlie  veins  of  the  back  of  the  hand  and  forearm  should  be  dissected  out  before 
removing  the  superficial  fascia.  These  veins  are  the  radial  and  the  anterior  and 
the  posterior  nlnar.  The  radial  and  anterior  ulnar  pass  to  the  front  of  the  forearm 
just  above  the  wrist,  while  the  posterior  ulnar  continues  on  the  back  of  the  forearm 
almost  as  far  as  the  elbow.  These  veins  commence  on  the  back  of  the  hand  in  a 
plexus  which  receives  the  veins  of  the  fingers.  The  radial  vein  arises  from  the 
outer  side  of  the  plexus,  while  the  anterior  and  posterior  ulnar  arise  from  the  inner 
side  of  the  plexus.  The  veins  of  the  fingers  commence  in  a  plexus  situated  around 
the  matrix  of  the  nail. 

The  lymphatics  on  the  back  of  the  fingers  terminate  in  a  plexus  on  the  back 
of  the  hand,  from  which  vessels  pass  up  the  back  of  the  forearm  and  around  the 
radial  and  ulnar  borders  to  join  those  on  the  anterior  surface. 

DISSECTION. — Reflect  the  superficial  fascia  and  trace  the  nerves.  The  super- 
ficial nerves  seen  upon  the  back  of  the  forearm  and  hand  are  the  musculo-cuta- 
neous,  the  inferior  external  cutaneous  branch  of  the  musculo-spiral,  the  lesser 
internal  cutaneous,  the  internal  cutaneous,  radial,  and  ulnar  nerves. 

The  posterior  branch  of  the  musculo-cutaneous  nerve  passes  to  the  back  of 
the  forearm  over  the  prominence  formed  by  the  supinator  longus  and  extensor 
carpi  radialis  longior  and  brevior  muscles  ;  it  supplies  the  skin  on  the  lower  two- 
thirds  of  the  back  and  outer  part  of  the  forearm,  as  far  as  the  wrist,  and  com- 
municates with  a  branch  of  the  radial  and  the  external  cutaneous  branch  of  the 
musculo-spiral. 

The  inferior  external  cutaneous  branch  of  the  musculo-spiral  nerve  enters 
the  forearm  in  front  of  the  outer  condyle  of  the  humerus,  supplies  the  skin  on  the 
outer  posterior  part  of  the  forearm,  and  terminates  on  the  back  of  the  hand.  It 
communicates  with  the  musculo-cutaneous  or  external  cutaneous  about  the  middle 
of  the  forearm. 

The  lesser  internal  cutaneous  nerve  terminates  in  the  skin  upon  the  inner 
side  of  the  olecranon,  and  communicates  with  the  internal  cutaneous  nerve. 

The  posterior  branch  of  the  internal  cutaneous  nerve  enters  the  back  of  the 
forearm  below  the  inner  condyle  of  the  humerus,  and  supplies  the  skin  over  the 


[96  SURGICAL   ANATOMY. 

inner  posterior  part  of  the-  forearm  from  the  elbow  to  the  wrist.  It  communicates 
with  the  dorsal  branch  of  the  ulnar  nerve. 

The  radial  nerve  reaches  the  hack  of  the  forearm  about  three  indies  above 
the  wrist,  by  passing  under  tlie  tendon  of  the  supinatnr  longus  muscle.  Near  the 
lower  end  of  the  radius  it.  gives  off  a  /xilm/n-  cutaneous  l>r<ni<-li  which  supplies  the 
radial  margin  of  the  hand  and  thumb,  and  then  divides  into  four  branches.  Of 
these,  one  supplies  the  ulnar  side  of  the  thumb, another  passes  to  the  radial  side  of 
the  index  finger,  a  third  divides  into  two  branches  to  supply  the  adjacent  sides  of 
the  index  and  middle  lingers,  and  a  fourth  communicates  with  a  branch  from  the 
dorsal  branch  of  the  ulnar  to  supply  the  contiguous  margins  of  the  middle  and 
ring  lingers. 

The  dorsal  cutaneous  branch  of  the  ulnar  nerve. — About  three  inches  above 
the  wrist  the  ulnar  nerve  gives  off  the  dorsal  cutaneous  branch,  which  passes  back- 
ward under  the  flexor  carpi  iilnaris  and  over  the  tendon  of  the  extensor  carpi 
ulnaris  to  the  back  of  the  wrist,  where  it  divides  into  a  communicating  and  two 
digital  branches.  The  inner  digital  branch  passes  to  the  inner  side  of  the  little 
finger,  while  the  outer  digital  branch  passes  to  the  middle  of  the  fourth  interosseous 
space,  where  it  divides  into  two  branches  for  the  supply  of  the  adjacent  sides  of 
the  little  and  ring  lingers.  The  communicating  branch  joins  a  filament  from  the 
radial  nerve,  and  aids  in  the  supply  of  the  contiguous  sides  of  the  ring  and  middle 
fingers. 

The  deep  fascia  of  the  back  of  the  forearm  is  stronger  than  that  of  the  front. 
It  is  attached,  above,  to  the  external  and  internal  condyles  of  the  humerus  and 
the  olecranon,  and  here  receives  expansions  from  the  bicipital  fascia  and  the  tendon 
of  the  triceps;  it  is  also  attached  to  the  posterior  border  of  the  ulna,  outer  border 
of  the  lower  end  of  the  radius,  and  the  pisiform  and  cuneiform  bones.  At  the 
wrist  the  deep  fascia  is  very  dense,  contains  many  transverse  fibers,  and  forms  the 
posterior  annular  ligament.  Beyond  the  posterior  annular  ligament  the  deep  fascia 
is  continued  upon  the  back  of  the  hand  as  a  delicate  membrane. 

DISSKCTIOX. — Incise  the  deep  fascia  transversely,  above  the  posterior  annular 
ligament,  and  reflect  it  from  below  upward,  as  it  is  very  firmly  attached  to  the 
muscles  in  the  upper  part  of  the  forearm.  The  posterior  annular  ligament  is 
left  in  place  in  order  to  permit  study  of  the  relations  of  the  structures  which  pass 
beneath. 

The  posterior  annular  ligament  is  that  thickened  portion  of  the  deep  fascia 
of  the  forearm  which  extends  obliquely  inward  from  the  outer  border  of  the  lower 
end  of  the  radius  to  the  pisiform  and  cuneiform  bones,  and  is  continuous  with  the 
deep  fascia  of  the  hypothenar  eminence.  From  the  under  surface  vertical  pro- 
cesses are  given  off  which  are  attached  to  ridges  on  the  posterior  surface  of  the 


TIII-:  HACK  or  mi-:  FOREARM.  i<.>: 

lower  end  of  the  radius.  \\\  means  of  these  processes  six  eoinpartnients  are 
formed  for  the  pa>sage  of  the  extensor  tendons.  They  contain,  from  within  out- 
ward, the  tendons  of  the  following  muscles:  The  extensor  carpi  ulnaris.  ihe 
extensor  of  the  little  finder  (extensor  minimi  digiti),  (lie  extensor  communis  digi- 
torum  and  extensor  indicis,  the  extensor  secmidi  internodii  pollicis.  the  extensor 
carpi  radialis  longior  and  brevior,  the  extensor  primii  internodii  pollicis,  and 
extensor  ossis  metacarpi  pollicis.  Kach  of  these  coin])artments  has  a  synovial 
lining  which  extends  above  and  below  the  limits  of  the  ligament.  The  sheaths  of 
tlu-  extensor  tendons,  particularly  those  of  the  thumb,  are  not  infrequently  the 
site  of  inflammation  (teno-synovitis),  and  in  such  cases  there  is  a  longitudinal 
swelling  over  the  position  of  the  tendon,  due  to  increase  in  the  amount  of  secretion 
in  the  synovial  sheath.  There  is,  also,  a  grating  or  crepitating  sensation  commu- 
nicated to  the  surgeon's  linger  when  the  patient  contracts  the  various  muscles 
(tenalgia  crepitans).  Tubercular  teno-synovitis  may  also  occur  here.  Connected 
with  the  tendon  sheaths,  or,  more  commonly,  with  the  periarticular  structures  of 
the  -wrist,  we  often  meet  with  small,  firm,  oval,  or  round  swellings  which  are 
rendered  more  prominent  by  flexion  of  the  wrist,  and  are  known  as  ganglia. 
They  are  more  common  in  young  girls. 

The  extensor  sheaths  of  the  tendons  of  the  back  of  the  hand  are  practically 
prolongations  of  the  walls  of  the  different  compartments  of  the  posterior  annular 
ligament.  They  hold  the  same  relations  as  the  compartments,  and  inclose  the 
same  tendons  which  have  been  described  as  occupying  the  compartments  of  the 
posterior  annular  ligament. 

The  muscles  exposed  are  the  extensors  of  the  hand  and  fingers.  They  consist 
of  three  sets — the  radial,  superficial,  and  deep  extensors. 

Radial  extensors. — Supinator  longus,  extensor  carpi  radialis  longior,  and 
extensor  carpi  radialis  brevior. 

The  supinator  longus,  supinator  radii  longus  or  brachio-radialis,  arises  from 
the  upper  two-thirds  of  the  external  condyloid  ridge  of  the  humerus,  as  high  up  as 
the  musculo-spiral  groove,  and  from  the  external  intermuscular  septum.  It  is  a 
long  fleshy  muscle,  the  belly  of  which,  with  the  other  two  muscles  of  this  group, 
forms  the  prominence  of  the  outer  side  of  the  forearm.  Its  flattened  tendon  is 
inserted  into  the  base  of  the  styloid  process  of  the  radius.  It  is  wholly  sub- 
cutaneous except  at  the  lower  part  of  its  tendon,  where  it  its  crossed  obliquely  by 
the  extensores  ossis  metacarpi  and  primi  internodii  pollicis.  It  rests  upon  the 
musculo-spiral  nerve,  the  radial  recurrent  artery,  the  radial  vessels  and  nerve,  the 
humerus,  the  supinator  brevis  muscle,  the  extensores  carpi  radialis  longior  and 
brevior  muscles,  and  the  insertion  of  the  pronator  radii  teres.  On  its  inner  side 
above  the  elbow  are  the  braehialis  anticus  muscle,  musculo-spiral  nerve,  and  radial 


IDS  SURGICAL   ^^. \TOMY. 

recurrent  artery  ;  and  below  the  elbow,  the  tendon  of  the  biceps  and  the  pronator 
radii  tores. 

I>L(>OI>  Sri'i-i.Y. — From  the  radial  and  radial  recurrent  arteries. 

XKKVK  SriTLV. — From  the  musculo-spiral  nerve. 

ACTION. — It  slightly  supinates  the  forearm,  especially  after  full  pronation, 
flexes  the  forearm,  and  in  full  supination  is  a  slight  pronator. 

The  extensor  carpi  radialis  longior  arises  from  the  lower  third  of  the  external 
condyloid  ridge  of  the  humerus,  the  external  intermuscular  septum,  and  from  the 
external  condyle  of  the  humerus  by  the  common  extensor  tendon;  the  filters 
terminate  about  the  middle  of  the  forearm  in  a  flattened  tendon,  which  passes 
do\vn  the  outer  side  of  the  forearm  to  the  wrist,  and  through  a  groove  upon  the 
back  of  the  base  of  the  radius  just  behind  the  styloid  process,  accompanied  by  the 
extensor  carpi  radialis  brevier,  to  be  inserted  upon  the  radial  side  of  the  base  of 
the  metacarpal  bone  of  the  index  finger.  The  muscle  is  overlapped  on  its  outer 
'anterior  border  by  the  supinator  longus.  and  crossed  at  its  lower  end  by  the  three 
extensors  of  the  thumb.  It  lies  upon  the  elbow-joint,  extensor  carpi  radialis 
brevior,  and  dorsum  of  the  wrist. 

BLOOD  SrrpLY. — From  the  radial  and  radial  recurrent  arteries. 

NKKVK  SI'PPLY. —  From  the  nmscnlo-spiral  nerve. 

ACTION. — It  extends  and  abducts  the  wrist  and  flexes  the  elbow. 

The  extensor  carpi  radialis  brevior  arises  from  the  external  condyle  of  the 
humerus,  the  adjacent  intermuscular  septum,  the  external  lateral  ligament  of  the 
elbow-joint,  and  the  deep  fascia.  In  the  middle  of  the  forearm  it  ends  in  a 
flattened  tendon  which  lies  close  to  and  accompanies  that  of  the  extensor  carpi 
radialis  longior  down  the  forearm.  It  passes  through  the  groove  upon  the  base  of 
the  radius  and  is  inserted  into  the  radial  side  of  the  base  of  the  metacarpal  bone 
of  the  middle  finger.  It  and  the  tendon  of  the  extensor  carpi  radialis  longior 
occupy  the  same  sheath  and  pass  through  the  same  compartment  of  the  posterior 
annular  ligament.  Above  it  is  covered  by  the  extensor  carpi  radialis  longior,  and 
below  by  the  extensors  of  the  thumb.  It  rests  upon  the  supinator  brevis,  the 
insertion  of  the  pronator  radii  tores,  the  radius,  and  carpus;  and  upon  its  nlnar 
side  is  in  contact  with  the  extensor  communis  digitorum. 

BLOOD  SrppLY. — From  the  radial  and  radial  re-current  arteries. 

N  KRVE  SuppLY.-'-From  the  posterior  interosseous  nerve. 

ACTION. — It  extends  the  wrist  and,  feebly,  the  elbow. 

Superficial  Extensors. — The  extensor  communis  digitorum,  the  extensor 
minimi  digiti,  the  extensor  carpi  ulnaris,  and  the  anconeus. 

The  extensor  communis  digitorum  muscle  arises,  by  the  common  extensor 
tendon,  from  the  external  condyle  of  the  humerus,  the  deep  fascia,  and  adjacent 


PLATE  LV. 


Triceps  tendon 

Dinar  n 
Posterior  ulnar  recurrent  a 

Flexor  carpi  ulnaris  m. 
Flexor  piofundus  digitorum  m 


Extensor  carpi  ulnaris  tendon 

Posterior  interosseous  n. 

Posterior  carpal  a. 

Ganglion  of  Wrisberg 

Radial  a.- 


WL  i 


I 


Biceps  in. 
Brachialis  anticus  m. 

.Supinator  iongus  m. 
Superior  profunda  a. 


Extensor  carpi  radialis  longior  m. 
Musculo-spiral  n, 

Anconeus  m.(cut) 
Posterior  interosseous  recurrent  a. 


-Supinator  brevis  m. 

—  Posterior  interosseous  n. 
-Posterior  interosseous  a. 

Extensor  ossis  metacarpi  pollicis  m. 

Radius 

Extensor  carpi  radialis  brevior  tendon 
Extensor  carpi  radialis  longior  tendon 
Extensor  primi  internodii   pollicis  m. 
Extensor  secundi  internodii  pollicis  m. 

Extensor  indicis  m. 

Extensor  carpi  radialis  longior  tendon 

Extensor  carpi  radialis  brevior  tendon 
Posterior  carpal  a. 

Dorsales  pollicis  a. 
—  Metacarpal  a. 
Dorsalis  indicis  a. 


DEEP  MUSCLES  OF  BACK  OF  FOREARM,  POSTERIOR  INTEROSSEOUS  ARTERY  AND  NERVE, 

200 


THE  r.ACK   OF  THE   FOREARM.  -'01 

intermuscular  septa.  Just  below  the  middle  of  the  forearm  it  divides  into  three 
tendons  which  pass,  with  the  extensor  indicis,  through  a  common  compartment  in 
tin'  posterior  annular  ligament,  whence  they  diverge  for  insertion  into  the  hases  of 
the  second  and  third  phalanges  of  the  four  fingers.  The  muscle  is  subcutaneous, 
except  where  its  tendons  pass  heneath  the  posterior  annular  ligament,  and  lies 
upon  llie  supinator  hivvis,  extensors  of  the  thuiiih  and  index  finger,  the  posterior 
interosseous  nerve  and  vessels,  the  carpus  and  tlie  dorsal  interossei  muscles.  On 
its  ulnar  side  are  the  extensor  minimi  digiti  and  extensor  carpi  ulnaris. 

Ui.ooD  SUPPLY. — From  the  posterior  interosseous  artery. 

XF.KVE  SUPPLY. — From  the  posterior  interosseous  nerve. 

ACTION. — Its  chief  function  is  to  extend  the  phalanges;  continuing  its  action 
it  extends  the  wrist-joint  and,  to  a  slight  extent,  the  elbow. 

The  extensor  minimi  digiti  muscle  lies  upon  the  ulnar  side  of  the  extensor 
connnunis  digitorum  muscle,  and  is  generally  connected  therewith.  It  arises  from 
the  external  condyle  of  the  htimerus  by  the  common  extensor  tendon,  from  the 
deep  fascia,  and  the  adjacent  intermuscular  septa.  It  becomes  tendinous  in  the 
lower  part  of  the  forearm,  and  passes  behind  the  radio-uluar  joint  through  a 
separate  compartment  of  the  posterior  annular  ligament  of  the  wrist.  It  passes 
to  the  back  of  the  little  finger  after  uniting  with  the  tendon  of  the  extensor 
connnnnis  digitorum.  It  is  covered  above  by  the  extensor  communis  digitorum 
and  extensor  carpi  ulnaris,  but  is  superficial  below,  except  where  it  lies  beneath  the 
posterior  annular  ligament.  It  rests  upon  the  supinator  brevis,  the  extensor  ossis 
metacarpi  pollicis,  the  extensor  secundi  internodii  pollicis,  and  the  extensor  indicis. 

BLOOD  SUPPLY. — From  the  posterior  interosseous  artery. 

NERVE  SUPPLY. — From  the  posterior  interosseous  nerve. 

ACTION. — It  extends  the  wrist-joint,  the  metacarpo-phalangeal  and  the  intcr- 
phalangeal  joints  of  the  little  finger. 

The  extensor  carpi  ulnaris  muscle  arises,  by  the  common  extensor  tendon, 
from  the  external  condyle  of  the  humerus,  from  the  middle  third  of  the  posterior 
border  of  the  ulna  in  common  with  the  flexor  carpi  ulnaris  and  flexor  profundus 
digitorum,  and  from  the  deep  fascia.  It  lies,  superficially,  upon  the  ulnar  side  of 
the  forearm,  and  ends  in  a  tendon  which  goes  through  a  groove,  back  of  the 
styloid  process  of  the  ulna  and  beneath  the  posterior  annular  ligament,  to  be 
inserted  into  the  base  of  the  metacarpal  bone  of  the  little  finger.  It  is  subcuta- 
neous, except  where  it  lies  beneath  the  posterior  annular  ligament,  and  rests  upon 
the  supinator  brevis,  extensor  ossis  metacarpi  pollicis,  and  extensores  primi  and 
secundi  internodii  pollicis,  extensor  indicis,  the  ulna,  and  the  carpus.  Its  ulnar 
border  is  in  relation  with  the  anconeus  and  the  posterior  border  of  the  ulna ;  its 
radial  border  with  the  extensor  minimi  digiti. 


202  SURGICAL    ANATOMY. 

BLOOD  SriTLY. — From  the  posterior  intcrosscous  artery. 

XKI;VK  Si'i>ri,Y. —  From  the  posterior  iniemsseous  nerve. 

ACTION. —  It  extends  the  elbow-joint  and  adducts  and  extends  the  wrist-joint. 

The  anconeus  is  a  small  and  triangular-shaped  muscle,  situated  upon  the 
outer  side  of  the  olecranon.  It  arises  from  the  hack  of  the  external  condvle  of  the 
humerus  and  the  posterior  ligament  of  the  elbow-joint.  From  this  origin  its  libers 
diverge  for  insertion  into  the  outer  side  of  the  olecranon  and  upper  one-fourth  of 
the  shaft  of  the  ulna.  It  is  superficial  and  lies  against  the  elbow-joint,  the 
orbicular  ligament,  the  ulna,  and  a  part  of  the  supinator  brevis.  Its  upper  edge 
is  in  contact  with  and  parallel  to  the  lowermost  fillers  of  the  outer  head  of  the 
triceps;  its  lower  and  outer  margin  adjoins  the  extensor  carpi  ulnaris. 

BLOOD  SUPPLY. — From  the  interosseous  recurrent  artery. 

NKKVK  SUPPLY. — From  the  musculo-spiral  nerve. 

ACTION. — It  extends  the  elbow-joint. 

DISSECTION. — The  extensor  communis  digitorum,  extensor  minimi  digiti,  and 
extensor  carpi  ulnaris  should  now  be  severed  in  the  middle  of  the  forearm,  and 
reflected  upward  and  downward  so  that  greater  facility  for  the  study  of  the  follow- 
ing muscles  may  be  afforded. 

Deep  Extensors:  Supinator  brevis,  extensor  ossis  metacarpi  pollicis,  ex- 
tensor primi  internodii  pollicis,  extensor  secundi  internodii  pollicis,  and  extensor 
indicis. 

The  supinator  radii  brevis  or  supinator  brevis  is  a  broad,  flat  muscle, 
irregular  in  outline,  and  wrapped  about  the  upper  end  of  the  radius.  It  arises 
from  the  external  condvle  of  the  humerus,  the  external  lateral  ligament  of  the 
elbow-joint,  the  orbicular  ligament  of  the  radius,  the  depression  below  the  lesser 
sigmoid  cavity  of  the  ulna,  and  the  fascia  enveloping  the  muscle.  Its  upper  libers, 
arranged  as  a  loop,  surround  the  neck  of  the  radius,  and  are  inserted  into  the  back 
of  its  inner  surface,  while  the  remainder  of  the  muscle  is  attached  to  the  anterior 
and  outer  surface  of  the  radius,  from  the  oblique  line  and  bicipital  tuberosity  to 
the  insertion  of  the  pronator  radii  teres.  It  is  covered  in  front  and  externally  by 
the  biceps,  pronator  radii  teres,  supinator  longus,  extensores  carpi  radialis  longior 
and  brevier,  and  the  radial  vessels  and  nerve;  behind  by  the  anconeus,  extensor 
communis  digitorum,  extensor  minimi  digiti,  extensor  carpi  ulnaris,  and  the 
int ei-<isseous  recurrent  artery.  It  rests  upon  the  elbow-joint,  the  superior  radio- 
ulnar  joint,  and  the  radius.  It  is  pierced  by  the  posterior  interosseous  nerve. 

BLOOD  SUPPLY. — From  the  radial  and  iuterosseous  recurrent  arteries. 

NERVE  SUPPLY. — From  the  posterior  interosseous  nerve. 

ACTION. — It  is  the  most  powerful  supinator  of  the  forearm,  and  helps  to  keep 
the  head  of  the  radius  in  position. 


PLATE  LVI. 


Triceps  tendon 


Dinar  n. 
Posterior  ulnar  recurrent  a 


Flexor  carpi  ulnaris  m 
Anterior  interosseous  a. 


Flexor  profundus  digitorum 


Posterior  carpal  a. 


Biceps  m. 

Supinator  longus  m. 
Superior  profunda  a. 


Extensor  carpi  radialis  longior  m 
Brachialis  anticus  m. 

Musculo-spiral  n. 

Anconeus  m.(cut) 
Posterior  interosseous  recurrent  a. 

Supinator  brevis  m. 
Common  interosseous  a. 
Posterior  interosseous  n. 


Posterior  interosseous  a. 


nterosseous  membrane 


Anterior  interosseous  a. 


Radial  a. 

Posterior  carpal  a. 
Metacarpal  a. 


ANTERIOR  AND  POSTERIOR  INTEROSSEOUS  ARTERIES. 
203 


PLATE  LVII, 


Extensor  communis  digitorum  tendons-jl- 
Extensor  carpi  ulnaris  tendon — I 


Extensor  carpi  radialis  brevior  tendon 

Extensor  carpi  radialis  longior  tendon 
Posterior  carpal  a: 

Dorsal  interosseous  a. 

Radial  a. 
Extensor  minimi  digiti  tendon 

Dorsal  interosseous  m. 
Abductor  minimi  digiti  m: 

Vinculae 


Extensor  primi  internodii  pollicis  tendon 
Extensor  secundi  internodii  pollicis  tendon 

Posterior  annular  ligament 

xtensor  ossis  metacarpi  pollicis  tendon 
Posterior  carpal  a. 
Metacarpal  a. 

Dorsales  pollicis  a. 

Extensor  indicis  tendon 
Abductor  indicis  m. 


Inner  head  of  flexor 
brevis  pollicis  m. 


Adductor  pollicis  m. 
Dorsalis  indicis  a. 


TENDONS  AND  ARTERIES  OF  BACK  OF  HAND. 
206 


7V//-;  JIACK  OF  THK  FOUKAUU.  207 

The  extensor  ossis  metacarpi  pollicis  muscle  arise-  ['mm  the  back  of  the 
sliafl  of  the  radius  and  ulna  from  a  surface  ahout  two  inches  long  and  just  below 
the  inferior  margins  of  the  supinator  brevis  and  anconeiis  muscles,  and  the  interven- 
ing interosseous  iuenil)rane.  It  passes  obliquely  downward  and  outward,  its  tendon 
going  through  a  groove  U|)on  the  radius,  external  to  the  styloid  process  and  in 
common  with  that  of  the  extensor  primi  internodii  pollicis,  to  be  inserted  into  the 
radial  side  of  the  base  of  the  metacarpal  bone  of  the  thumb.  It  is  covered  by  the 
extensores  communis  digitorum,  carpi  uhiaris,  and  minimi  digiti,  and  the  posterior 
annular  ligament,  and  is  crossed  by  the  posterior  interosseous  nerve  and  vessels. 
It  lies  upon  the  ulna,  interosseous  membrane,  radius,  extensores  primi  internodii 
pollicis  and  secundi  internodii  pollicis,  tendons  of  the  extensores  carpi  radialis 
longior  and  brevior,  the  radial  vessels,  and  the  wrist-joint.  Above  it  are  the  supi- 
nator brevis  and  aneoneus,  and  below  it  the  extensores  primi  and  secundi  internodii 
pollicis. 

BLOOD  SUPPLY. — From  the  posterior  interosseous  artery. 

NERVE  SUPPLY.— From  the  posterior  interosseous  nerve. 

ACTION. — It  abducts  and  extends  the  metacarpal  bone  of  the  thumb,  abducts 
the  wrist-joint,  and  supinates  the  forearm. 

The  extensor  primi  internodii  pollicis,  or  extensor  brevis  pollicis  muscle, 
the  smallest  of  the  extensors  of  the  thumb,  arises  from  the  back  of  the  shaft  of 
the  radius  and  the  interosseous  membrane  just  below  the  extensor  ossis  metacarpi 
pollicis  muscle,  and  takes  a  course  parallel  with  that  muscle  and  external  to  the 
styloid  process  of  the  radius.  It  passes  through  the  same  groove  as  the  extensor 
ossis  metacarpi  pollicis  to  be  inserted  into  the  base  of  the  first  phalanx  of  the 
thumb.  It  lies  upon  the  radius  and  interosseous  membrane,  the  tendons  of  the 
extensores  carpi  radialis  longior  and  brevior,  the  radial  vessels,  the  wrist-joint, 
the  metacarpal  bone  of  the  thumb,  and  the  metacarpo-phalangeal  joint  of  the 
thumb.  Its  upper  border  is  in  relation  with  the  preceding  muscle.  It  is  covered 
by  the  extensor  ossis  metacarpi  pollicis,  extensor  communis  digitorum,  extensor 
minimi  digiti,  and  the  posterior  annular  ligament. 

BLOOD  SUPPLY. — From  the  posterior  interosseous  artery. 

NERVE  SUPPLY. — From  the  posterior  interosseous  nerve. 

ACTION. — It  extends  the  first  joint  of  the  thumb,  abducts  and  extends  the 
metacarpal  bone  of  the  thumb,  and  abducts  the  hand. 

The  extensor  secundi  internodii  pollicis,  or  extensor  longus  pollicis  muscle, 
larger  than  the  preceding  muscle,  arises  from  the  back  of  the  shaft  of  the  ulna  and 
the  interosseous  membrane,  below  the  attachment  of  the  extensor  ossis  metacarpi 
pollicis,  and  ends  in  a  tendon  which  passes  through  a  separate  groove  upon  the 
back  of  the  radius,  and,  obliquely,  across  the  wrist  and  tendons  of  the  extensores 


SURGICAL    A  ^  ATOMY. 

carpi  radialis  longior  and  brevior,  for  insertion  into  the  back  of  the  base  of  the  last 
phalanx  of  the  thumb.  At  the  wrist,  in  the  triangular  interval  between  the 
extensor  secundi  internodii  pollicis  and  tin-  other  i  \vo  tlnimb  extensor  tendons,  ilie 
radial  artery  will  be  found.  The  muscle  and  tendon  are  eovered  by  the  extensor 
ossis  metaearpi  pollicK  extensor  eommunis  digitornm,  extensor  niinimi  digiti, 
cxlen^or  carpi  uliiaris,  the  posterior  interosseous  artery  and  (Misierior  annular  liga- 
ment. It  rests  upon  the  interosseous  membrane,  the  tendons  of  the  extensores 
carpi  radialis  longior  and  brevior.  the  radius,  the  wrist-joint,  the  radial  vessels, 
the  metaearpal  bone  of  the  thumb  and  its  proximal  phalanx. 

Hi.oon  Srrri,Y. —  From  the  posterior  interosseous  artery. 

NEHVK  SITI-LY. — From  the  posterior  interosseous  nerve. 

ACTION. — It  extends  all  of  the  thumb-joints,  addnets  the  metaearpal  bone  of 
the  thumb,  abducts  the  hand,  and  supinates  the  forearm. 

The  extensor  indicis  muscle,  narrow  and  elongated,  arises  from  the  back  of 
the  ulna  and  the  interosseous  membrane,  below  the  attachment  of  the  extensor 
seeundi  internodii  pollicis  muscle,  whence  it  passes,  with  the  outer  tendon  of  the 
extensor  eommunis  digitorum,  through  the  same  compartment,  beneath  the  posterior 
annular  ligament,  to  be  inserted  into  the  inner  side  of  that  tendon.  It  is  covered 
by  the  extensor  eommunis  digitorum,  extensor  minimi  digiti,  extensor  seeundi 
internodii  pollicis,  and  the  posterior  annular  ligament.  Tt  lies  upon  the  inter- 
osseous membrane,  the  wrist,  and  the  dorsal  interosseous  muscle  of  the  second 
interosseous  space. 

BLOOD  Sci'Pi.v. — From  the  posterior  interosseous  artery. 

NEKVIC  Sci'i'LY. — From  the  posterior  interosseous  nerve. 

ACTION. — It  extends  the  wrist-joint,  the  metacarpo-phalangeal  and  the  inter- 
phalangeal  joints  of  the  index -finger. 

The  posterior  interosseous  artery  is  the  branch  of  the  common  interosseous 
which  passes  backward  between  the  bones  of  the  forearm  and  the  upper  border  of 
the  interosseous  membrane  and  oblique  ligament.  It  emerges  behind,  between  the 
supinator  brevis  muscle  above  and  the  extensor  ossis  metaearpi  pollicis  muscle  below, 
where  it  gives  off  an  ascending  branch — the  •!,itn-(i»xroiiK  -m-m-rciit.  In  addition 
to  the  interosseous  recurrent  artery  it  gives  oil'  muxi-u.liir  and  <ii-t!cul<ir  bnmclirx. 
It  continues  downward  over  the  ulnar  origin  of  the  extensor  ossis  metaearpi  pollicis, 
extensor  primi  internodii  pollicis,  extensor  seeundi  internodii  pollicis,  and  the 
extensor  indicis,  and  anastomoses  with  the  termination  of  the  anterior  interosseous 
after  that  artery  has  passed  through  the  interosseous  membrane,  and  then  with  the 
posterior  carpal  branches  of  the  radial  and  ulnar  arteries.  The  interosseous  recur- 
rent artery  is  quite  a  large  branch,  which  ascends  between  the  supinator  brevis 
and  anconeus  muscles  to  the  sulcus  between  the  external  coudyle  of  the  humerus 


Tin:  r,.\(  'K  or  Tin:  IIAM>.  209 


and  olccranon  process  of  the  ulna:  it  anastomoses  with  the  superior  ii 
anastomotica  magna,  radial  recurrent,  and  posterior  ulnar  recurrent  arteries. 
The  iiiiixciiltti-  lii-iuii-liix  of  the  posterior  interosseous  artery  supply  the  muscles 
I  «-t\veen  which  it  lies.  The  ni-ticulni-  /irnit<-licx  supply  the  wrist-joint. 

The  tn-iiiiiKtt  /ifiiii'ni  <,f  tlif  anterior  interosseous  artery  is  seen  lying  on 
the  posterior  surface  of  the  lower  part  of  the  interosseous  membrane,  where  il  is 
joined  hy  a  hranch  of  the  posterior  interosseous  artery.  ll  runs  downward  over 
the  wrist,  heneath  the  extensor  tendons,  and  anastomoses  with  the  posterior  carpal 
arch. 

The  posterior  interosseous  nerve  winds  around  the  outer  side  of  the  upper 
end  of  the  radius,  through  the  substance  of  the  supinator  hrevis  muscle,  to  the 
hack  of  the  forearm,  whence  it  passes  downward,  in  company  with  the  posterior 
interosseous  artery,  between  the  superficial  and  deep  extensor  muscles,  to  the  upper 
border  of  the  extensor  secundi  internodii  pollicis.  In  the  forearm  it  supplies 
nii/xrulfii-  /irinir/ii'x  to  the  extensor  carpi  radialis  brevior,  supinator  brevis,  extensor 
conimunis  digitorum,  extensor  minimi  digiti,  extensor  carjii  ulnaris,  extensor  ossis 
metacarpi  pollicis,  extensores  primi  and  secundi  internodii  pollicis,  and  extensor 
indicis.  At  the  upper  border  of  the  extensor  secundi  internodii  pollicis  muscle 
the  posterior  interosseous  nerve  leaves  the  posterior  interosseous  artery  and  runs 
beneath  the  extensor  secundi  internodii  pollicis  and  extensor  indicis,  upon  the 
interosseous  membrane,  and  accompanies  the  terminal  part  tof  the  anterior  inter- 
osseous artery  to  the  back  of  the  wrist.  Here  it  ends  in  a  ganglitbnn  enlargement 
which  gives  off  articular  filaments  to  the  wrist  and  intercarpal  joints. 

After  blows  upon  the  front  of  the  external  condyle  or  outer  side  of  the  upper 
one-fifth  of  the  radius,  the  condition  of  the  posterior  interosseous  nerve  may  cause 
spasm  or  paralysis  of  the  supinator  brevis  and  the  extensors  of  the  wrist  and 
ringers,  excepting  the  radial  extensors  which  are  supplied  by  branches  of  the 
musculo-spiral  before  it  bifurcates. 


THE  BACK  OF  THE  HAND. 

The  superficial  veins,  nerves,  and  deep  fascia  of  the  back  of  the  hand  having 
been  described  when  the  posterior  surface  of  the  forearm  was  considered,  it  remains 
to  reflect  the  deep  fascia  from  above  downward  in  order  to  expose  the  extensor 
tendons  and  remaining  deep  structures  of  the  back  of  the  hand. 

The  extensor  tendons  emerge  from  beneath  the  posterior  annular  ligament 
and  diverge  for  insertion  into  the  backs  of  their  respective  digits.  Those  of  the 

14 


210  SURGICAL   A  \.\TOMY. 

extensor  communis  digitorum  become  narrow  ami  thickened  opposite  the  nieta- 
carpo-phalangeal  joints,  at  which  point  they  give  off  fasciculi  which  arc  attached  to 
the  lateral  ligaments  of  these  articulations.  They  then  form  a  broad  aponeurosie 
which  covers  the  entire  back  of  the  iirst  phalanges,  where  they  are  joined  by  the 
tendons  of  the  intcrossei  and  lumbricales  muscles.  Opposite  the  first  interphalan- 
gcal  joint  each  tendon  divides  into  a  middle  slip  which  is  inserted  into  the  base  of 
the  second  phalanx,  and  two  lateral  .slips  which  unite  over  the  middle  phalanx. 
for  insertion  into  the  back  of  the  base  of  the  terminal  phalanx.  These  tendons 
constitute  the  posterior  ligaments  of  the  metacarpo-phalangeal  and  interphalangeal 
joints.  On  the  proximal  side  of  the  metacarpo-phalangeal  articulations  the  tendon 
of  the  ring  finger  sends  off  two  lateral  divergent  slips,  which  arc  attached  to  the 
adjacent  tendons  of  the  little  and  middle  fingers.  This  is  important  because  it 
restricts  the  independent  extension  of  the  ring  finger,  a  defect  especially  troublesome 
in  pianists  and  violinists,  who,  sometimes,  by  reason  of  this  interference  with  the 
required  movement,  have  these  restricting  bands  divided.  The  tendon  of  the 
middle  linger  is  also  connected  to  the  extensor  communis  tendon  of  the  index  finger 
by  a  band  of  transverse  fibers.  The  tendon  of  the  extensor  indicis  joins  that  of 
the  common  extensor  over  the  first  phalanx  of  the  index  finger.  The  tendon  of 
the  extensor  minimi  digit i  divides,  one  part  joining  the  common  extensor  tendon 
of  the  little  linger,  the  other,  ending  in  the  dorsal  expansion  common  to  this 
tendon  and  that  of  the  tendon  of  the  extensor  communis  digit orum. 

DISSKCTJOX. — Remove  the  fascia  overlying  the  dorsal  interossei  muscles  and 
the  vessels  of  the  back  of  the  wrist  and  hand.  The  vessels  on  the  back  of  the 
wrist  and  band  are  the  radial  artery  and  its  branches,  which  will  be  described 
below,  the  posterior  carpal  branch  of  the  ulnar  artery,  and  the  terminal  portion 
of  the  anterior  interosseous  artery. 

The  radial  artery,  as  it  leaves  the  front  of  the  forearm,  first  lies  upon  the 
external  lateral  ligament  of  the  wrist,  then  upon  .the  scaphoid,  trapc/ium,  and  base 
of  the  metacarpal  bone  of  the  thumb,  and  under  the  tendons  of  the  extensoivs 
ossis  m  eta  carpi,  primi  internodii,  and  secundi  internodii  pollicis,  whence  it  continues 
to  the  apex  of  the  interval  situated  between  the  metacarpal  bones  of  the  thumb 
and  index-finger,  where  it  passes,  between  the  two  heads  of  the  first  dorsal  interos- 
seous muscle,  into  the  palm.  On  the  back  of  the  wrist  it  gives  off  the  posterior  carpul, 
metacarpal  or  first  dorsal  interosseous,  dorsalis  pollicis,  and  dorxulix  //«//<•/*  tn-tt  /•/<•*. 

The  posterior  carpal  artery  arises  on  the  outer  side  of  the  wrist,  and  passes 
across  the  carpal  bones  beneath  the  extensor  tendons.  It  joins  a  corresponding 
branch  from  the  ulnar  artery  and  forms  beneath  the  tendons  the  posterior  carpal 
arch.  From  this  arch  arise  the  second  and  third  interosseous  iirfrri/-*,  which 
pass  downward  over  the  third  and  fourth  interosseous  intervals,  and  divide  into 


THE  RACK    <)!••   THE  HAM).  ~>\\ 

dorsal  digital  branches  which  supply  the  contiguous  sides  of  the  middle,  ring. 
and  little  fingers.  At  the  carpal  ends  of  the  interosseous  spaces  they  are  joined 
by  the  perforating  brunches  of  the  deep  palmar  arch.  At  the  distal  ends  of  the 
interosseous  spaces  they  give  oil'  mili'fio,-  ji,  rj»i-<itln</  brunches  which  join  the 
digital  arteries  of  the  corresponding  intervals.  The  posterior  carpal  arch  is  joined 
by  the  terminal  portion  of  the  anterior  interosseous  artery.  The  posterior  carpal 
/irtinch  of  the  nfmir  nr/< ,-;/  arises  from  the  latter  vessel  a  short  distance  above  the 
pisiform  bone,  and  winds  around  the  ulna  beneath  the  flexor  carpi  ulnaris  to  the 
back  of  the  wrist,  where  it  lies  beneath  the  extensor  tendons  and  anastomoses 
•with  the  posterior  carpal  branch  of  the  radial  artery  to  form  the  posterior  carpal 
arch  which  has  been  described  above.  The  terminal  portion  of  the  anterior 
interosseous  arterv  has  been  described  with  the  back  of  the  forearm. 

The  metacarpal  or  first  dorsal  interosseous  artery  generally  arises  from 
the  radial,  although,  at  times,  it  comes  from  the  posterior  carpal  arch.  It  passes 
downward  over  the  second  interosseous  space  and  divides  into  dorsal  digital 
branches  which  supply  the  adjacent  sides  of  the  index  and  middle  fingers.  Like 
the  second  and  third  interosseous  arteries  it  is  joined  by  a  perforating  brunch  from 
the  deep  palmar  arch,  and  gives  off  an  anterior  perforating  branch  to  join  the 
corresponding  digital  artery. 

The  dorsal  digital  arteries  terminate  at  the  first  interphalangeal  joints,  where 
they  anastomose  with  the  posterior  branches  of  the  collateral  digital  arteries. 

The  dorsales  pollicis  arteries,  two  branches,  arise  from  the  radial  near  the 
base  of  the  first  metacarpal  bone,  and  pass  downward  on  either  side  of  the  thumb. 

The  dorsalis  indicis  artery  arises  from  the  radial  immediately  before  it 
passes  into  the  palm,  and  runs  over  the  abductor  indicis  muscle,  on  the  radial 
side  of  the  metacarpal  bone  and  first  phalanx  of  the  index  finger,  to  anas- 
tomose opposite  the  first  interphalangeal  joint  with  a  posterior  branch  of  the 
radialis  indicis  artery. 

The  dorsal  interossei  are  four  bipenniform  muscles  which  arise  from  the 
adjacent  sides  of  the  proximal  one-half  or  two-thirds  of  the  shafts  of  the  metacarpal 
bones ;  the  origin  is  more  extensive  from  the  metacarpal  bones  of  the  fingers 
into  which  they  are  inserted.  They  are  numbered  in  order  from  the  radial  side 
and  are  inserted  into  the  bases  of  the  first  phalanges  and  extensor  tendons  of  the 
index,  middle,  and  ring  fingers.  The  first  and  largest  dorsal  interosseous  or  abduc- 
tor indicis  is  inserted  into  the  radial  side  of  the  base  of  the  first  phalanx  and  the 
extensor  tendon  of  the  index  finger ;  the  second  is  inserted  into  the  radial  side  of 
the  base  of  the  first  phalanx  and  the  extensor  tendon  of  the  middle  finger;  the 
third  into  the  ulnar  side  of  the  base  of  the  first  phalanx  and  the  extensor  tendon 
of  the  middle  finger ;  and  the  fourth  into  the  ulnar  side  of  the  base  of  the  first 


SURGICAL    ANATOMY. 

phalanx  and  the-  extensor  tendon  of  the  ring  linger.  The  intervals  between  the 
liases  of  the  nietaearpal  bones  and  the  converging  fibers  of  the  proximal  ends  of  the 
muscles  permit  the  passive  of  the  perforating  hranehes  from  the  deep  palmar  arch. 
The  interval  between  the  origins  of  the  lirst  dorsal  interosseous  muscle  gives 
passage  to  the  radial  artery. 

BLOOD  iSri'i'i.v. — These  muscles  are  supplied  by  (lie  deep  palmar  and  posterior 
carpal  arches. 

NERVE  St  ri'i.v. — From  the  deep  branch  of  the  ulnar  nerve. 

ACTION. — They  are  abductors  of  the  fingers,  flex  the  metacarpo-phalangeal 
joints,  and  extend  the  last  two  phalanges.  The  action  of  the  first  dorsal  inter- 
osseous  (abductor  indicis)  is  clearly  demonstrated  by  abducting  the  index  finger, 
flexing  its  metacarpo-phalangeal  joint,  and  keeping  the  last  two  phalanges 
extended,  thus  contracting  the  muscle,  which  can  be  plainly  felt  and  seen  on 
the  back  of  the  hand  in  the  first  interosseous  space. 


JOINTS. 

A  joint  is  composed  of  the  adjacent  portions  of  two  or  more  hones,  articular 
cartilage,  ligaments,  and  one  or  two  synovial  membranes. 

The  articular  ends  of  the  bones  are  chiefly  composed  of  cancellous  tissue, 
which  gives  strength,  elasticity,  a  large  surface  for  articulation,  and  a  minimum 
weight.  At  the  articular  surface  the  cancellous  tissue  is  covered  by  a  thin  crust 
of  dense,  compact  bone  which  contains  no  Haversian  canals.  The  articular  ends 
of  the  long  bones  are  supplied  by  the  articular  arteries,  and  thus  have  a  blood 
supply  independent  of  that  furnished  to  the  shaft  by  the  nutrient  artery.  This 
portion  of  the  bone  is  occasionally  affected  by  inflammation,  which  is  frequently 
tubercular  in  character.  If  the  diseased  tissue  is  not  removed  and  drainage 
instituted,  the  thin  crust  of  compact  bone  upon  the  articular  surface  offers  but 
slight  obstruction  to  the  inflammatory  process,  and  the  articular  cartilage  and 
joint  may  soon  become  involved. 

The  articular  cartilage  covers  the  smooth  articular  ends  of  the  bones.  It  is 
of  the  hyaline  variety,  and  contains  no  blood-vessels.  It  receives  its  nourishment 
through  lymph  channels  which  pass  between  the  cartilage  cells.  The  lymph  is 
derived  from  the  vessels  in  the  ends  of  the  bones  and  in  the  synovial  membrane  of 
the  joint ;  therefore,  if  the  cartilage  be  partially  detached  from  the  bone  by 
external  violence,  the  detached  area  loses  more  or  less  of  its  blood  supply,  and 
necrosis  may  result.  In  rheumatoid  arthritis  this  cartilage  disappears  and  the 
articular  surfaces  of  the  bones  become  hard  and  eburnated. 


PLATE  LVIII. 


Anterior  sterno-clavicular  ligament 


Interclavicular  ligament 

Interarticular  cartilage 

Rhomboid  ligament 


f 


STERNO-CLAVICULAR  JOINT-ANTERIOR  VIEW. 


Interclavicular  ligament 


Posterior  sterno-ciavicular  iigament 


Rhomboid  ligament 


STERNO-CLAVICULAR  JOINT-POSTERIOR  VIEW. 
214 


JO/.VVN  OF  THE  rrri'.i;  EXTREMITY.  215 

A  synovial  membrane  is  found  in  all  true  joints.  In  joints  like  tlie  temporo- 
maxilkiy,  which  have  an  interarticular  cartilage  .subdividing  tlu>  joint,  there  are 
two  synovial  saes.  This  membrane  lines  the  ligaments  of  the  joint  and  fades  away 
at  the  margin  of  the  articular  cartilage,  where  it  is  continuous  with  the  surface  of 
the  cartilage.  The  synovial  membranes  resemble  serous  membranes,  and,  like  them, 
are  composed  of  flat  endothelial  cells.  They  secrete  the  synovial  fluid  which  lubri- 
cates the  joints.  Inflammation  of  joints  begins  in  this  membrane  more  frequently 
than  in  other  parts  of  the  joint.  Because  of  the  dose  relation  between  the  mem- 
brane and  the  ligaments,  the  latter  are  likely  to  be  involved.  In  tubercular 
arthritis  the  softening  of  the  ligaments  permits  increased  lateral  motion  of  the 
joint,  whereas  the  infiltration  and  contraction  of  the  ligaments  and  bands  of  adhe- 
sions in  rheumatic  arthritis  cause  stillness  and  false  ankylosis  of  the  joint. 

For  practical  purposes  all  joints  maybe  divided  into  three  classes:  Those 
which  derive  their  strength  chiefly  from  the  conformation  of  the  bones,  those 
whose  strength  depends  upon  their  ligaments,  and  those  which  largely  depend 
upon  surrounding  muscles  for  support.  The  hip-joint  is  the  best  example  of  the 
first  class.  ICxternal  violence  applied  to  such  a  joint  is  more  likely  to  produce  a 
contusion  than  a  sprain  or  dislocation.  In  joints  of  the  second  class,  such  as  the 
radio-ulnar,  a  sprain  is  more  common  than  a  contusion  or  a  dislocation.  In 
joints  of  the  third  class,  the  best  example  of  which  is  the  shoulder,  dislocation  is 
more  common  than  contusion  or  sprain. 

In  the  diagnosis  of  fractures,  dislocations,  and  diseases  of  joints  of  the  extrem- 
ities it  is  always  advisable  to  compare  the  affected  with  the  non-affected  member. 


JOINTS  OF  THE  UPPER  EXTREMITY. 

The  joints  of  the  upper  extremity  include  the  sterno-clavicular,  the  scapulo- 
clavicular,  the  shoulder  or  scapulo-humeral,  the  elbow,  the  superior  and  infe- 
rior radio-ulnar,  the  radio-carpal  or  wrist,  the  intercarpal  or  medio-carpal,  the 
carpo-metacarpal,  the  metacarpo-phalangeal,  and  the  interphalangeal. 


THE  STERNO-CLAVICULAR  JOINT. 

The  sterno-clavicular,  an  arthrodial  joint,  is  formed  by  the  upper  outer  part 
of  the  manubrium  stern i  and  the  inner  end  of  the  clavicle,  which  is  larger  than 
the  bed  or  articulating  surface  of  the  manubrium  in  which  it  rests.  The  first 
costal  cartilage  gives  attachment  to  one  of  the  ligaments  of  the  joint.  These  parts 


216  SURGICAL  ANATOMY. 

are  bound  together  by  five  ligaments :  The  anterior  sterno-clavicular,  the  posterior 
sterno-clavicular,  the  interclavicular,  the  costo-clavicular  or  rhomboid,  and  the 
interarticular  fibro-cartilage. 

The  anterior  sterno-clavicular  ligament,  which  covers  the  front  of  the  joint, 
is  a  fibrous  membrane  extending  from  the  superior  and  anterior  surface  of  the 
inner  end  of  the  clavicle  to  the  superior  and  anterior  surface  of  Hie  inanubrium 
sterni.  It  is  covered  by  the  skin,  the  fascia',  and  the  sternal  origin  of  the  stern o- 
cleido-mastoid,  and  it  is  in  relation  posteriorly  with  the  intern rtictilar  libro-cartiiage 
and  the  two  synovial  sacs. 

The  posterior  sterno-clavicular  ligament  is  attached  to  the  hack  of  the  inner 
end  of  the  clavicle  and  to  the  manubrium  sterni  in  a  manner  similar  to  that  of 
the  anterior  ligament.  Anterior  to  the  ligament  are  the  interarticular  fibro- 
cartilage  and  the  two  synovial  sacs  ;  posterior  to  it  arc  the  sterno-hyoid  and  sterno- 
thyroid  muscles. 

The  interclavicular  ligament  is  a  strong  fibrous  band  which  varies  consider- 
ably in  size,  and  extends  from  the  superior  surface  of  the  sternal  end  of  one  clavicle 
to  the  same  part  of  the  other.  It  is  attached  to  the  superior  surface  of  the  manu- 
brium sterni  between  the  ends  of  the  clavicles,  and  is  covered  in  front  by  the  skin 
and  fascia1,  while  behind  it  is  in  relation  with  the  sterno-thyroid  muscles. 

The  costo-clavicular  (rhomboid)  ligament,  short,  flat,  and  quadrangular  in 
shape,  is  attached  below  to  the  upper  surface  of  the  inner  end  of  the  cartilage  of 
the  first  rib,  and  above  to  the  rhomboid  depression  on  the  under  surface  of  the 
sternal  end  of  the  clavicle.  It  lies  behind  the  tendon  of  origin  of  the  subclavius 
muscle  and  in  front  of  the  subclavian  vein.  In  order  to  expose  the  interarticular 
fibro-cartilage  sever  the  costo-clavicular  and  the  anterior  sterno-clavicular  liga- 
ment. 

The  interarticular  cartilage,  a  flat  disc  nearly  corresponding  in  size  and 
outline  to  the  sternal  end  of  the  clavicle,  is  situated  between  the  end  of  the  clavicle 
and  the  clavicular  notch  of  the  sternum,  where  it  acts  as  a  buffer  and  prevents  the 
clavicle  from  being  pushed  inward  over  the  sternum.  Below  it  is  attached  to  the 
first  chondro-sternal  junction,  and  above  to  the  upper  and  back  part  of  the  inner 
end  of  the  clavicle,  where  it  blends  with  the  interclavicular  ligament  and  the 
anterior  and  posterior  ligaments.  It  is  thinnest  in  the  center,  and  thickest  at  its 
upper  posterior  part.  The  joint  is  divided  by  this  fibre-cartilaginous  disc  into  two 
compartments,  each  one  of  which  has  a  separate  synovial  sac.  These  sacs,  the 
inner  of  which  is  the  larger,  sometimes  communicate  by  means  of  an  opening 
present  in  the  cartilage. 

BLOOD  SUPPLY. — Derived  from  the  internal  mammary,  superior  thoracic,  and 
supra-scapular  arteries. 


PLATE  LIX, 


Spine  of  scapula 


Conoid  ligament 

Frapezoid  ligament 

Inferior  acromio-clavicular  ligament 

Superior  acromio-clavicular  ligament 
Coraco-acroinlal  ligament 

Coraco-humeial  ligament 


Transverse  ligament 


Long  head  of  biceps  m. 


Capsular  ligament 


SCAPULO-GLAVICULAR,  ACROMIO-CLAVICULAR,  AND  SCAPULO-HUMERAL  JOINTS.-ANTERIOR  VIEW, 

218 


PLATE  LX, 


Coraco-acromial  ligament  Superior  acromio-clavicular  ligament 


Conoid  ligament 


Transverse  ligament- 


Trapezoid  ligament 


Long  head  of  biceps  m. 


Cut  edge  of  capsular  ligament 

Glenoid  ligament 
Glenoid  cavity 


-   • 

f 


-Long  head  of  triceps  m 


SCAPULO-CLAVICULAR  AND  AGROMIO-CLAVICULAR  JOINTS,  AND  GLENOID  LIGAMENT, 

219 


JOINTS   OF   THE    UPPER   EXTREMITY.  221 

NERVE  SUPPLY. — The  nerve  supply  of  the  joint  is  derived  from  the  branch 
of  the  bnichial  plexus  which  supplies  the  subclavius  muscle. 

MOVEMENTS. — This  joint  is  the  center  of  motion  for  the  shoulder,  and  admits 
of  cdrcumduction  and  of  limited  movement  upward,  downward,  forward,  and 
backward.  Dislocation  of  the  clavicle  at  this  articulation  does  not  often  occur, 
for  the  combined  strength  of  the  ligaments  is  considerable,  and  compensates  for 
the  lack  of  adaptation  of  the  articular  surfaces  of  the  bones.  The  adjacent 
muscles  assist  in  preventing  luxation. 


THE  SCAPULO-CLAVICULAR  JOINT. 

The  scapulo-clavicular,  an  arthrodial  joint,  is  formed  by  the  acromial  end  of 
the  clavicle  and  the  acromion  process  of  the  scapula.  The  bones  are  held  in  place 
by  the  ligaments  proper,  which  are  the  superior  acromio-clavicular,  the  inferior 
acromio-clavicular,  and  the  iuterarticular  fibro-cartilage.  The  coraco-clavicular 
is  an  accessory  ligament. 

The  superior  acromio-clavicular  ligament  covers  the  upper  surface  of  the 
joint  and  is  attached  to  the  contiguous  margins  of  the  two  bones.  It  is  quadri- 
lateral in  shape,  and  composed  of  parallel  transverse  fibers  which  interlace  with 
the  tendinous  fibers  of  the  trapezius  and  deltoid  muscles.  It  is  covered  by  skin 
and  fascia?. 

The  inferior  acromio-clavicular  ligament  is  the  counterpart  of  the  preceding, 
covers  the  under  surface  of  the  joint,  and  is  similarly  attached.  Below  it  is  in 
relation  with  the  tendon  of  the  supra-spinatus  muscle.  These  two  ligaments  are 
continuous  around  the  joint  and  constitute  its  capsule. 

An  interarticular  nbro-cartilage  sometimes  exists  in  this  joint.  When  present 
it  is  rarely  a  complete  disc,  and  occupies  the  upper  part  of  the  joint.  There  is  but 
one  synovial  membrane.  The  cartilage  when  present  can  be  exposed  by  dividing 
the  superior  acromio-clavicular  ligament. 

The  coraco-clavicular  ligament — composed  of  two  parts,  the  trapezoid  and 
conoid — connects  the  clavicle  and  the  coracoid  process  of  the  scapula.  The  trape- 
zoid ligament,  the  anterior  of  the  two,  is  quadrilateral  in  shape,  and  is  attached  to 
the  upper  surface  of  the  coracoid  process  and  to  the  oblique  ridge  on  the  under 
surface  of  the  clavicle.  Behind  it  is  continuous  with  the  conoid  ligament,  while  in 
front  and  externally  it  has  a  free  margin.  The  conoid  ligament,  triangular  in 
shape,  is  attached  by  its  apex  to  a  rough  impression  upon  the  base  of  the  coracoid 
process  on  the  inner  side  of  the  trapezoid  ligament ;  by  its  base  to  the  conoid 
tubercle,  and  for  half  an  inch  to  a  ridge  on  the  under  surface  of  the  clavicle. 
In  front  and  externally  the  conoid  ligament  is  continuous  with  the  trapezoid. 


222  SURGICAL   ANATOMY. 

Tliis  ligament  is  in  relation  with  the  subclavius  and  deltoid  muscles  in  front,  and 
with  areolar  tissue,  i'at,  and  the  insertion  of  the  t rape/his  behind. 

MOVKMKXTS. — This  joint  permits  a  slight  gliding,  rotatory,  or  forward  and 
backward  movement,  limited  by  (lie  two  portions  of  the  coraco-clavicular  ligament. 

Upward  dislocation  of  the  outer  end  of  the  clavicle  is  not  uncommon;  it  is 
characterized  by  an  undue  prominence  of  the  outer  end  of  the  bon 

BLOOD  SUPPLY. — The  nourishment  of  the  joint  is  derived  from  the  supra- 
scapular,  acromio-thoracic,  and  posterior  circumflex  arteries. 

NERVE  SUPPLY. — The  supra-scapular  and  circumflex  nerves  supply  the 
articulation. 

The  ligaments  proper  of  the  scapula  are  the1  coraco-acromial  and  the  trans- 
verse ligaments. 

The  coraco-acromial  ligament,  triangular  in  shape,  is  attached  by  its  base  to 
the  entire  outer  border  of  the  coracoid  process ;  by  its  apex  to  the  tip  of  the 
acromion  process.  It  completes  the  coraco-acromial  arch,  which  is  above  the  head 
of  the  hnmerus.  It  is  covered  by  the  clavicle  and  deltoid  muscle  and  separated 
from  the  capsular  ligament  of  the  shoulder-joint  by  a  bursa. 

The  transverse  or  supra-scapular  ligament  bridges  over  the  supra-scapular 
notch,  converting  it  into  a  foramen  which  gives  passage  to  the  supra-scapular 
nerve.  The  supra-scapular  vessels  pass  over  it. 

In  dislocation  of  the  scapula  the  inferior  angle  of  the  bone  slips  from  under 
the  upper  portion  of  the  latissimn.s  dorsi  muscle,  and  the  condition  which  results 
is  "winged  scapula."  The  causes  are  general  weakness  of  the  muscles,  as  in 
pulmonary  tuberculosis  and  paralysis  of  the  serratus  inagnus  muscle.  The  inferior 
angle  is  normally  held  against  the  chest  by  the  latissimus  dorsi  and  serratus 
inagnus,  consequently  any  condition  which  weakens  these  muscles  allows  this 
angle  to  project.  In  the  treatment  of  this  condition  the  scapula  should  be  held 
against  the  chest  by  a  broad  belt,  so  that  the  extent  of  movement  of  the  arm  will 
not  be  much  restricted.  The  condition  of  the  muscles  may  be  improved  by 
massage,  electricity,  and  hypodermic  injection  of  strychnin. 


THE  SHOULDER-JOINT. 

The  shoulder,  an  enarthrodial  or  ball-and-socket  joint,  is  formed  by  the 
glenoid  fossa  of  the  scapula  and  the  head  of  the  humerus,  which  are  united  by 
the  capsular  and  coraco-humeral  ligaments.  The  glenoid  fossa  is  deepened  by 
the  glenoid  ligament  which  is  attached  to  its  margin.  The  deepened  glenoid 
fossa  is  much  smaller  than  the  head  of  the  humerus,  to  allow  of  greater  freedom 
of  motion. 


JOINTS   OF  THE  UPPER    EXTHEMITY. 

The  capsular  ligament  is  attached  to  the  margin  of  the  glenoid  cavity  of  the 
scapula  and  to  the  anatomic  neck  of  the  huinerus.  Tlie  capsule  is  very  loose,  or 
sacciform,  to  permit  free  movement  ;  it  is  thickest  above.  The  capsular  ligament 
is  perforated  at  three  points :  Above,  where  the  bursse  beneath  the  tendons  of  the 
infra-spinatns  and  subscapnlaris  communicate  with  tin-  shoulder-joint,  and  on  the 
outer  side,  where  the  long  tendon  of  the  biceps  pierces  it  between  the  tuberosities 
oft  lie  linmerus.  The  three  </!<  u/i-liuim  i'nl  liiiixlx  or  ligaments  are  merely  tliickened 
portions  of  the  capsule  on  its  inner  and  anterior  aspect. 

The  coraco-humeral  or  accessory  ligament  is  a  thickening  of  the  part  of 
the  capsule  extending  from  the  outer  border  of  the  coracoid  process  to  the  greater 
tuberosity  of  the  huinerus,  some  of  the  fibers  being  raised  from  the  capsule  and 
thus  becoming  dignified  into  a  separate  ligament. 

The  glenoid  ligament  is  a  dense  fibre-cartilaginous  rim  situated  upon  the 
edge  of  the  glenoid  cavity  and  possessing  a  wide  attachment  and  thin  border;  it  is 
continuous  above  with  the  long  head  of  the  bice] is.  and  below  with  the  long  head 
of  the  triceps.  It  deepens  the  glenoid  cavity  and  protects  both  the  edge  of  the 
cavity  and  the  head  of  the  humerus  from  the  effects  of  sudden  impacts  and  severe 
pressure. 

The  synovial  membrane  lines  the  ligamentous  walls  of  the  joint,  is  reflected 
upon  the  neck  of  the  humerus  and  is  continuous  with  the  margin  of  the  articular 
cartilage  which  covers  the  head  of  the  humerus  and  the  glenoid  cavity  of  the 
scapula.  It  sends  a  reflection  around  the  long  tendon  of  the  biceps  where  it  lies 
within  the  capsule  of  the  joint  and  above  the  head  of  the  humerus,  and  has 
communication  with  a  bursal  sac  situated  between  the  capsule  and  the  tendon 
of  the  subscapularis  muscle,  and  occasionally,  with  another  bursal  sac  placed 
between  the  capsule  and  the  tendon  of  the  infra-spinatua  A  large  bursa,  which, 
however,  does  not  communicate  with  the  shoulder-joint,  lies  between  the  deltoid 
muscle  and  the  capsular  ligament.  Through  the  communications  which  exist 
between  the  joint  cavity  and  these  synovial  bursse  pus  may  find  its  way  to  the 
surface,  and  ultimately  form  sinuses. 

In  acute  synovitis  of  the  shoulder-joint  the  synovial  sac  becomes  distended 
with  fluid,  and  as  the  synovial  sac  in  relation  with  the  long  head  of  the  biceps 
is  a  process  of  the  synovial  membrane  of  the  joint,  a  fluctuating  swelling  may  be 
detected  upon  each  side  of  that  tendon.  The  arm  is  lengthened  by  the  pressure 
of  the  fluid  ;  it  may  be  lifted  into  its  normal  position,  but  it  immediately  lengthens 
after  the  support  is  removed.  Acute  synovitis  of  the  shoulder  may  be  mistaken 
for  inflammation  of  the  subacromial  bursa,  as  either  condition  may  be  caused  by  a 
twist  of  the  arm.  In  the  former  condition  there  is  pain  on  moving  the  ann  in  any 
direction,  whereas  in  inflammation  of  the  acromial  bursa  the  pain  is  much  more 


224  SURGICAL  ANATOMY. 

marked  in  abduction  of  the  arm,  as  this  movement  causes  compression  of  ihr 
bursa. 

The  muscles  protecting  the  joint  are,  in  front,  the  subscapularis ;  above,  the 
supra-spinatus  and  long  tendon  of  the  biceps;  behind,  the  infra-spinatua  and  teivs 
minor;  below,  the  long  head  of  the  triceps.  The  deltoid  covers  the  joint  above 
and  behind,  and,  while  protecting  it  from  direct  injury,  aids  in  the  retention  of  the 
head  of  the  humerus  within  its  socket.  The  joint  is  also  protected  above  by  the 
acromio-clavicular  arch  and  the  coraco-acromial  ligament.  The  long  tendon  of 
origin  of  the  biceps,  lying  between  the  tnherosities  of  the  humerus  in  an  osteo- 
iibrous  canal,  strengthens  the  joint  and  steadies  the  head  of  the  humerus  in 
its  various  movements. 

MOVEMENT  in  all  directions,  affording  gliding,  anteduction,  retroduction, 
adduction,  abduction,  and  circumduction,  is  possible  at  the  shoulder-joint.  The 
most  limited  movements  are  backward  and  upward.  Persistence  in  the  former 
movement  causes  the  scapula  to  recede  toward  the  median  line  of  the  body,  and, 
in  the  latter,  the  inferior  scapular  angle  to  rotate  forward  and  outward.  In  cases 
of  ankylosis  of  the  shoulder-joint  the  movement  of  the  scapula  compensates,  to  a 
certain  extent,  for  the  loss  of  motion  in  the  scapulo-humeral  articulation.  Free 
movement  in  the  shoulder-joint  is  permitted  by  the  small  glenoid  cavity  and  large 
rounded  articulating  surface  of  the  head  of  the  humerus  and  the  laxity  of  the 
capsular  ligament.  Although  the  capsule  is  loose,  pinching  of  the  ligament  or 
synovia!  membrane  rarely  occurs,  being  prevented  by  the  partial  insertion  of 
the  subscapularis,  supra-spinatus,  and  infra-spinatus  muscles  into  the  capsular 
ligament. 

BLOOD  SUPPLY. — Derived  from  the  subscapular,  anterior  and  posterior  circum- 
flex, and  suprascapular  arteries. 

NERVE  SUPPLY. — The  shoulder-joint  is  supplied  by  the  circumflex  and  supra- 
scapular  nerves. 

THE  ELBOW-JOINT. 

The  elbow  is  a  ginglymus  or  hinge-joint,  and  is  formed  by  the  contiguous 
articular  surfaces  of  the  humerus,  ulna,  and  radius,  together  with  their  connecting 
ligaments.  The  lower  end  of  the  humerus  is  divided  into  two  articular  surfaces — 
an  inner,  larger,  and  an  outer,  smaller ;  the  former,  the  trochlear  surface,  articu- 
lates with  the  greater  sigmoid  cavity  of  the  ulna,  while  the  latter,  the  capitellum, 
with  the  head  of  the  radius.  The  upper  end  of  the  ulna,  by  its  greater  sigmoid 
cavity,  grasps  the  trochlear  surface  of  the  humerus  as  a  monkey-wrench  does  a 
screw-nut ;  this  is  seen  after  a  vertical  section  through  the  joint  involving  and 
dividing  the  olecranon  and  coronoid  processes.  The  radio-humeral  junction  is 


PLATE  LXI. 


Anterior  ligament 
External  lateral  li 
Orbicular  ligamen 
Oblique  ligame 


V 


Posterior  ligament 


ELBOW  JOINT,  — EXTERNAL  VIEW. 


Internal  lateral  ligament 
Posterior  ligament 


15 


ELBOW  JOINT, -INTERNAL  VIEW. 
225 


Anterior  ligament 


cular  ligament 


Biceps  tendon 


ique  ligament 


JOLXTS    OF   THE   ITPER    EXTREMITY.  '2'27 

secondary  to  the  preceding.  While  the  head  of  the  radius,  through  its  concavity, 
glides  forward  and  backward  during  movements  of  the  ulna,  the  principal  function 
of  this  articulation  is  to  allow  rotation  of  the  head  of  the  radius  in  pronation  and 
supination  of  the  forearm. 

The  condyles  of  the  humerus,  which  give  attachment  to  powerful  muscles  of 
the  forearm,  project  beyond  the  joint  upon  each  side.  Behind  the  joint  is  the 
prominence  of  the  olecranon,  into  which  is  inserted  the  extensor  tendon  of  the 
triceps.  In  front  of  the  joint  at  the  bottom  of  the  antecubital  fossa  is  found  the 
coronoid  process  of  the  ulna,  into  the  base  of  which  is  inserted  the  brachialis 
anticus.  In  the  outer  part  of  the  fossa,  deeply  placed,  is  the  tuberosity  of  the 
radius,  into  which  the  tendon  of  the  biceps  is  inserted. 

The  bones  are  held  in  position  by  ligaments  and  muscles — the  latter  having 
been  fully  described.  The  ligaments  consist  of  the  external  lateral,  the  internal 
lateral,  an  anterior,  and  a  posterior.  These  are  all,  really,  but  portions  of  one 
capsular  ligament  which  embraces  the  superior  radio-ulnar  in  addition  to  the 
elbow-joint. 

The  external  lateral  ligament  is  short,  and  at  its  attachment  to  the  external 
condyle,  is  narrow.  It  expands  as  it  descends,  and  is  attached  to  the  orbicular 
ligament  which  surrounds  the  head  of  the  radius,  to  the  neck  of  the  radius  and  to 
the  ulna,  posterior  to  its  lesser  sigmoid  cavity.  Its  fibers  are  fused  with  the  origin 
of  the  supinator  brevis. 

The  internal  lateral  ligament,  fan-shaped,  is  attached  above  by  its  apex  to 
the  internal  condyle.  Passing  downward  it  expands  and  may  be  divided  into  an 
anterior  and  a  posterior  portion  ;  the  anterior  portion,  is  attached  to  the  inner  side 
of  the  coronoid  process  ;  and  the  posterior  to  the  inner  side  of  the  olecranon.  Both 
portions  are  attached  to  the  ridge  between  the  coronoid  and  olecranon  processes  of 
the  ulna.  It  is  in  contact  with  the  triceps  and  flexor  carpi  ulnaris  muscles  and  the 
ulnar  nerve. 

The  lateral  ligaments  are  strong  and  tense  and  prevent  any  lateral  movement. 
If  lateral  movement  be  possible,  the  joint  is  disorganized  by  disease,  usually 
tubercular  ;  or  a  dislocation  exists. 

The  anterior  ligament  extends  across  the  front  of  the  joint.  It  is  attached  to 
the  anterior  surface  of  the  humerus  above  the  coronoid  fossa,  the  anterior  edge  of 
the  coronoid  process,  the  anterior  surface  of  the  orbicular  ligament,  and  the  neck 
of  the  radius.  It  is  continuous  with  the  internal  and  external  lateral  ligaments, 
and  is  covered  by  the  brachialis  anticus  muscle. 

The  posterior  ligament  extends  from  the  upper  margin  of  the  olecranon 
fossa  to  the  superior  and  external  margins  of  the  olecranon  process  and  to  the 
orbicular  ligament.  It  is  covered  by  the  triceps  and  the  anconeus ;  the  deepest 


228  SURGICAL  ANATOMY. 

portion  of  the  former  muscle,  the  subanconeus,  supports  and  draws  up  the  thin 
posterior  ligament  during  extension  of  the  joint  and  prevents  pinching  of  the 
synovial  membrane. 

The  synovial  membrane  lines  the  joint  surface  of  the  ligaments,  and  is 
reflected  upon  the  margins  of  the  articulating  surfaces  of  the  bones  which  enter 
into  the  formation  of  the  joint,  It  is  continuous  with  the  synovial  sac  of  the 
superior  radio-ulnar  joint.  There  is  more  or  less  adipose  tissue  between  the 
capsule  of  the  joint  and  the  synovial  membrane  where  the  latter  is  reflected  from 
the  ligaments  to  and  upon  the  margins  of  the  articulating  surfaces,  especially  at 
the  radial,  coronoid,  and  olecranon  fossa*. 

Bursae  near  the  elbow- joint. — There  is  a  small  bursa  over  the  head  of  the 
radius  between  the  common  extensor  tendon  of  origin  and  the  capsule ;  one 
between  the  tendon  of  the  triceps  and  part  of  the  upper  surface  of  the  olecranon 
process;  one  between  the  tendon  of  the  biceps  and  the  anterior  portion  of  the 
tuberosity  of  the  radius,  and  one  in  the  subcutaneous  tissue  over  the  olecranon. 
None  of  these  bursa?  communicates  with  the  joint. 

In  acute  synovitis  of  the  elbow-joint  the  synovial  sac  is  distended  with  fluid, 
and  instead  of  a  depression  on  either  side  of  the  olecranon  and  tendon  of  the 
triceps  there  is  a  swelling  with  an  intermediate  depression  which  in  position 
corresponds  to  the  above-mentioned  tendon  and  olecranon  process. 

MOVKMKNTS. — The  movements  of  the  elbow-joint  consist  only  of  flexion  and 
extension ;  flexion  is  checked  by  the  contact  of  the  soft  parts  of  the  forearm 
and  arm  ;  extension  by  the  tightening  of  the  ligamentous  and  muscular  structures 
on  the  anterior  aspect  of  the  joint.  It  must  not  be  forgotten  that  the  movements 
of  the  upper  radio-ulnar  articulation  are  entirely  independent  of  those  of  the 
elbow-joint.  The  motion  of  the  elbow-joint  is  purely  a  hinge  movement,  while 
that  of  the  superior  radio-ulnar  joint  is  rotatory.  In  flexion  and  extension  of 
the  forearm  the  head  of  the  radius  simply  glides  forward  and  backward  upon  the 
eapitellum  ;  in  supination  and  pronation  the  head  of  the  radius  has  a  rotatory 
motion  within  its  orbicular  ligament  and  the  lesser  sigmoid  cavity  of  the  ulna. 

BLOOD  SUPPLY. — Nourishment  is  supplied  to  the  joint  by  the  inosculating 
twigs  of  the  superior  and  inferior  profunda,  the  anastomotica  magna,  the  anterior 
and  posterior  ulnar  recurrent,  the  interosseous  recurrent,  and  the  radial  recurrent 
artery. 

NERVE  SUPPLY. — Derived  from  the  ulnar  nerve  as  it  lies  between  the  internal 
condyle  and  the  olecranon,  from  the  musculo-spiral,  musculo-cutaneous,  and 
median  nerves. 


PLATE  LXII. 


Ulna- 


Radius 

Interosseous  membrane 


Anterior  radio-ulnar  ligament 


Internal  lateral  ligament 
Anterior  radio-carpal  ligament 

External  lateral  ligament 


Anterior  annular  ligament 
Canal  for  flexor  carpi  radialis  tendon 


Capsular  ligament  of  first 
carpo-metacarpal  joint 


INFERIOR  RADIO-ULNAR  JOINT.-ANTERIOR  VIEW. 
230 


PLATE  LXIII. 


Posterior  radio-carpal  ligament 


External  lateral  ligament  of  wrist  joint. 


Capsular  ligament  of  corpo 
metacarpafjoint  of  thumb 


Posterior  radio-ulnar  ligament 


nternal lateral  '  , 


Dorsal  carpal  ligaments 


INFERIOR  RADIO-ULNAR,  RADIO-CARPAL,  INTERCARPAL,  AND  CARPO-METACARPAL  JOINTS, -POSTERIOR  VIEW. 

231 


JOINTS   OF  THE  UPPER   EXTREMITY. 


RADIO-ULNAR  ARTICULATIONS. 

The  movements  of  both  pronation  and  supinution  of  the  forearm  are  possible 
through  the  articulations  between  the  radius  and  the  ulna.  These  bones  may 
l>e  said  to  form  two  joints,  a  superior  and  an  inferior;  and  to  be  connected  in 
three  places,  at  the  superior  and  inferior  articulations  and  throughout  the  length 
of  their  shafts. 

The  Superior  Radio-ulnar  Articulation,  a  pivot-joint,  is  formed  by  the  recep- 
tion of  the  head  of  the  radius  into  the  lesser  sigmoid  cavity  of  the  ulna.  But 
one  ligament,  the  orbicular,  is  found  at  this  joint.  It  encircles  the  head  of  the 
radius  in  the  form  of  a  complete  ring,  as  it  passes  from  the  anterior  to  the 
posterior  border  of  the  lesser  sigmoid  cavity.  It  also  suspends  the  head  of  the 
radius,  as  its  lower  circumference  is  less  than  its  upper,  and  it  is  therefore  funnel- 
shaped.  It  is  intimately  blended  with  the  anterior,  posterior,  and  external  lateral 
ligaments  of  the  elbow-joint.  The  supinator  brevis  muscle  is  afforded  a  partial 
origin  from  this  ligament. 

The  synovial  membrane  of  this  articulation  is  continuous  with  that  of  the 
elbow-joint. 

BLOOD  AND  NERVE  SUPPLY.  —  Derived  from  the  same  sources  as  those  of  the 
elbow-joint. 

The  Inferior  Radio-ulnar  Articulation,  a  lateral  hinge-joint,  is  formed  by 
the  reception  of  the  head  (lower  end)  of  the  ulna  into  the  sigmoid  cavity  situated 
on  the  inner  side  of  the  base  of  the  radius.  A  thin  layer  of  cartilage  covers  the 
articular  surfaces  of  the  bones.  The  ligaments  of  the  joint  are  the  anterior  and 
posterior  radio-ulnar  and  the  triangular  nbro-cartilage. 

The  anterior  radio-ulnar  ligament  is  narrow,  and  passes  from  the 
anterior  border  of  the  sigmoid  cavity  of  the  radius  to  the  front  of  the  head 
of  the  ulna. 

The  posterior  radio-ulnar  ligament  is  similarly  attached  to  the  back  of 
the  joint. 

The  triangular  fibro-cartilage  separates  the  head  of  the  ulna  from  the 
cuneiform  bone  and  the  sigmoid  cavity  of  the  radius.  It  is  attached,  by  its 
apex,  to  the  depression  at  the  base  of  the  styloid  process  of  the  ulna,  and  by 
its  base  to  the  lower  end  of  the  radius,  along  the  lower  margin  of  the  sigmoid 
cavity.  It  is  united  by  its  margin  to  the  carpal  ligaments.  Its  apex  is  thick 
and  its  base  thin  ;  it  is  concave  above,  being  thicker  at  its  edges  than  at  its 
center.  At  times  the  center  is  perforated,  in  which  event  the  synovial  sac  of 
this  joint  is  continuous  with  that  of  the  wrist-joint.  When,  from  traumatism  or 
disease,  this  cartilage  becomes  detached  from  the  radius,  the  resulting  deformity 


•2:\\  SURGICAL    .I.V.I  TO  MY. 

is  an  abnormal  projection  of  the  head  of  the  ulna,  a  condition  frequently  cncoun- 
tt.Tcd  as  a  complication  and  sequel  of  Colics'  fracture. 

The  synovial  membrane  of  this  joint  is  so  loose  that  it  has  been  aptly  called 
the  sacciform  membrane;  this  laxity  is  necessary  to  permit  the  rotation  of  the 
base  of  the  radius  about  the  head  of  the  ulna  during  pronation  and  supination. 
The  triangular  tibro-cartilage  follows  the  base  of  the  radius  in  its  movements 
around  the  head  of  the  ulna. 

ULOOD  SriTT.Y. — The  nourishment  of  the  joint  is  derived  from  the  anterior 
intorosseous  artery  and  the  anterior  carpal  arch. 

XioiiVK  SrriM.v. — From  the  anterior  and  posterior  interosseous  nerve-. 

The  shafts  of  the  radius  and  ulna  are  also  connected  by  the  oblique  ligament 
and  the  interosseous  membrane. 

The  Oblique  ligament,  often  absent,  is  a  round  slip  which  passes  from  the 
outer  part  of  the  coronoid  process  of  the  ulna  to  the  radius  below  the  tuberosity. 
Its  direction  is  downward  and  outward.  It  lies  above  the  upper  border  of 
the  interosseous  membrane,  its  fibers  running  in  a  direction  at  a  right  angle 
to  those  of  the  membrane. 

The  interosseous  membrane  is  attached  to  the  interosscous  borders  of  the 
radius  and  ulna,  and  stretches  across  the  interval  existing  between  these  bones. 
It  is  deficient  above.  The  anterior  interosseous  vessels  pass  through  an  opening 
located  near  the  lower  end  of  this  membrane  to  reach  the  back  of  the  forearm. 
The  posterior  interosseous  artery  passes  between  the  upper  border  of  the  inter- 
osseous membrane  and  the  oblique  ligament  to  the  back  of  the  forearm.  The 
intero<seoiis  membrane  helps  hold  the  hones  together,  and  in  front  gives  a  greater 
surface  for  the  origin  of  the  llexor  profundus  digitorum  and  the  flexor  longus 
pollicis  muscle,  and  behind  for  the  origin  of  the.  three  extensors  of  the  thumb  and 
the  extensor  indicis. 

THE  RADIO-CARPAL  ARTICULATION. 

The  radio-carpal,  or  wrist,  a  double  ginglymus  or  hinge-joint,  is  formed  above 
by  the  lower  end  of  the  radius  and  the  under  surface  of  the  triangular  fibro- 
cartilage,  and  below  by  the  scaphoid,  semilunar,  and  cuneiform  bones  of  the  carpus. 
The  ulna  does  not  enter  into  the  formation  of  the  joint,  as  it  is  separated  from  it 
by  the  triangular  fibre-cartilage.  The  lower  end  of  the  radius,  with  the  triangular 
fibre-cartilage,  forms  a  concave  surface  into  which  the  three  bones  of  the  carpus 
which  form  a  smooth,  convex  surface  are  received.  The  surfaces  of  the  bones 
entering  into  the  formation  of  the  wrist-joint  are  covered  with  cartilage  and  firmly 
held  in  apposition  by  four  ligaments,  which  together  form  a  capsule.  These  four 
ligaments  are  the  external  lateral,  internal  lateral,  anterior,  and  posterior. 


PLATE  LXIV, 


Anterior  radio-ulnar  ligament 
Interosseous  membrane 

Anterior  radio-carpal  ligament 


Capsuiar  ligament 
Anterior  intercarpai  ligaments 
Anterior  carpo-metacarpa!  ligament 


INFERIOR  RADIO-ULNAR,  RADIO-CARPAL,  INTERCARPAL   AND  CARPO-METACARPAL  JOINTS, -ANTERIOR  VIEW. 

235 


./O/.V'/X    OF   T11K   UPPER    I-'.XTUI'M  ITY.  'l-M 

The  external  lateral  ligament  (external  radio-carpal)  extends  fnun  the  tip 
of  the  styloid  process  of  the  radius  to  the  outer  side  of  the  scaphoid.  A  few  of 
its  iil>ers  radiate  slightly  to  the  luliercle  of  the  scaphoid  and  the  ridge  of  the 
trape/ium,  while  others  pass  to  the  dorsal  surface  of  the  scaphoid.  The  external 
lateral  ligament  is  in  relation  with  the  radial  artery  and  the  tendons  of  the  exten- 
sores  ossis  inetacarpi  pollicis  and  primi  internodii  pollicis ;  the  artery  lies  hetween 
the  tendons  and  the  ligament. 

The  internal  lateral  ligament  (ulnocarpnl)  extends  from  the  extremity  of 
the  styloid  process  of  the  ulna  to  the  inner  surface  of  the  cuneiform  bone,  the  pisi- 
form hone,  and  the  anterior  annular  ligament.  It  is  fan-shaped,  its  lihers  radiat- 
ing to  a  more  marked  degree  than  do  those  of  the  external  lateral  ligament.  The 
lower  part  of  the  ligament  can  readily  be  divided  into  two  fasciculi,  one  of  which 
passes  to  the  inner  side  of  the  cuneiform  bone,  the  other  to  the  pisiform  bone  and 
anterior  annular  ligament. 

The  tendon  of  the  extensor  carpi  ulnaris  passes  over  the  posterior  part  of  the 
ligament. 

The  anterior  ligament  (anterior  radio-carpal)  is  a  broad,  thick  membrane 
which  is  attached  above  to  the  lower  end  of  the  radius,  its  styloid  process,  the 
triangular  fihro-cartilage,  and  ulna;  and  below  to  the  palmar  surface  of  the 
scaphoid,  semilunar,  and  cuneiform  bones.  A  few  of  the  fibers  are  continued 
downward  to  the  os  magnum  and  unciform  bones.  In  relation  with  the  anterior 
surface  of  the  ligament  are  the  tendons  of  the  flexor  profundus  digitorum  and 
flexor  longus  pollicis,  while  in  contact  with  the  posterior  surface  is  the  synovial 
membrane  of  the  joint.  Numerous  small  vessels  pierce  the  ligament. 

The  posterior  ligament  (posterior  radio-carpal),  not  so  strong  as  the  anterior, 
extends  from  the  posterior  surface  of  the  lower  end  of  the  radius  and  triangular 
fibro-cartilage  to  the  posterior  surface  of  the  scaphoid,  semilunar,  and  cuneiform 
bones.  It  is  strengthened  by  fibers  from  the  back  of  the  fibro-cartilage,  and  also 
by  the  fibrous  sheaths  of  the  extensor  secundi  internodii  pollicis  and  radial  exten- 
sors. The  other  extensor  tendons,  which  are  in  relation  with  the  posterior  surface 
of  the  ligament,  also  add  to  its  strength.  The  anterior  surface  is  in  relation  with 
the  synovial  membrane. 

The  synovial  membrane  lines  the  ligaments  of  the  joint  from  which  it  is 
reflected  to  the  margins  of  the  articular  surfaces  entering  into  the  formation  of 
the  joint.  It  is  very  lax  on  account  of  the  free  movement  of  the  joint.  It  does 
not  communicate  with  the  inferior  radio-ulnar  joint,  except  when  the  triangular 
fibro-cartilage  is  perforated.  It  is  not  in  communication  with  the  carpal  joints 
owing  to  the  intervention  of  the  interosseous  ligaments. 

In  acute  synovitis  of  the  wrist-joint  there  is  pain,  and  as  the  joint  is  super- 


238  vrnnicAL  AXATOMY. 

iicial.  heat  ami  redness  are  also  present.  Swelling  is  nio-t  pronounced  on  the 
dorsal  surface  as  the  subcutaneous  tissue  is  more  loosely  arranged  in  that  location, 
and  there  may  he  bulging  het\veen  the  extensor  tendons.  Acute  syiHivitis  is 
differentiated  from  teno-synovitis,  or  inflammation  of  the  sheaths  of  the  tendons, 
by  the  fact  that  when  the  wrist-joint  is  lixed  the  tinkers  can,  in  the  former  '-ondj- 
tion,  1)0  moved  without  producing  pain,  and  if  a  teno-synovitis  exists,  movement 
of  the  fingers  causes  pain. 

In  front  of  the  wrist-joint  are  the  flexor  tendons  of  the  hand,  and  behind  are 
the  extensors.  The  numerous  tendons  which  pass  over  the  wrist-joint,  and  the 
ill  irons  extensions  from  their  sheaths,  serve  to  strengthen  an  otherwise  ill 
protected  articulation. 

MOVKMKNTS. — The  movements  of  the  wrist-joint  are  very  similar  to  those 
of  a  ball-and-socket  joint,  the  main  difference  being  that  the  wrist  does  not 
possess  rotation.  This  loss  of  rotation  is  overcome  by  the  pronation  and  supina- 
tion  of  the  forearm,  which  is  effected  by  means  of  the  radio-ulnar  articulation-. 

BLOOD  STPPLY. —  Derived  from  the  anterior  and  posterior  carpal  arches,  the 
anterior  and  posterior  intcrosseous,  and  the  recurrent  carpal  branches  of  the 
deep  palmar  arch. 

NERVE  SUPPLY. — Derived  from  the  ulnar  and  the  posterior  interosseous  nerves. 

DISSECTION. — To  expose  the  articular  surfaces  of  the  joint,  cut  the  anterior 
and  lateral  ligaments  transversely  and  strongly  extend  the  hand. 


THE  CARPAL  JOINTS. 

The  articulations  of  the  bones  of  the  carpus  are  divided  into  three  sets — viz., 
those  between  the  bones  of  the  first  row,  those  between  the  bones  of  the  second  row, 
and  the  articulation  between  the  two  rows.  The  ligaments  of  the  first  row  of 
carpal  bones  are  two  dorsal,  two  palmar,  two  interosseous  fibro-cartilages,  and  the 
capsular  ligament  connecting  the  pisiform  and  cuneiform  bones. 

The  two  dorsal  ligaments  connect  the  dorsal  surfaces  of  the  bones — the 
scaphoid  with  the  semilunar  and  the  semilunar  with  the  cuneiform. 

The  two  palmar  ligaments  connect  the  anterior  surfaces  of  the  bones — the 
scaphoid  with  the  semilunar  and  the  semilunar  with  the  cuneiform.  The  palmar 
ligaments  are  stronger  than  the  dorsal. 

The  two  interosseous  fibro-cartilages  are  two  strips  of  cartilage  which  con- 
nect the  adjacent  surfaces  of  the  scaphoid  and  semilunar,  and  the  semilunar  and 
cuneiform.  They  fill  in  the  interstices  between  the  bones  and  help  form  the 
smooth  convex  surface  for  articulation  with  the  radius  and  triangular  fibro- 
cartilage.  The  pisiform  bone  is  attached  to  the  cuneiform  by  a  capsular  ligament. 


PLATE  LXV. 


SECTION  OF  JOINTS  OF  WRIST  AND  HAND. 
239 


JOLXTS   OF  Till':   I'l'l'Kl!    KXTlll'.M  1TY.  -> 41 

This  articulation  has  a  separate  synovial  membrane.  The  pisiform  i-<  also  attached 
to  the  unciforni  by  a  strong  palmar  band, — the  />ix<>-ii,i<-!niitc  lii/min  nt. — and  to  the 
base  of  the  iil'tli  metacarpal  bone  by  another  strong  palmar  band — the  />ix<>- 
nnli(aii-[>nl  Hi/in, a  nt.  These  palmar  bands  might  lie  regarded  as  prolongations 
from  the  tendon  of  the  Hexor  carpi  ulnaris  ;  and  the  pisiform  as  a  sesamoid  bone 
in  that  tendon. 

The  synovial  membrane  is  an  extension  of  that  lining  the  joint  between 
the  first  and  second  rows  of  carpal  bones. 

The  ligaments  of  the  second  row  of  carpal  bones  are  three  dorsal,  three  palmar. 
and  two  interosseons. 

The  three  dorsal  ligaments  connect  the  dorsal  surfaces  of  the  bones  of  the 
second  row — the  trapezium  with  the  trapezoid,  the  trapezoid  with  the  os  magnum, 
and  the  os  magnum  with  the  unciform. 

The  three  palmar  ligaments  connect  the  palmar  surfaces  of  the  bones  of  the 
second  row  in  the  same  manner  as  do  the  dorsal  ligaments.  The  palmar  ligaments 
are  stronger  than  the  dorsal. 

The  two  interosseous  ligaments  connect  the  unciform  with  the  os  magnum, 
and  the  os  magnum  with  the  trape/.oid.  At  times  there  is  a  third  interosseous 
ligament  found  between  the  trapezium  and  the  trapezoid. 

The  synovial  membrane  is  an  extension  of  that  lining  the  joint  between  the 
first  and  second  rows  or  the  medio-carpal  joint. 

The  Medio-carpal  Articulation  is  formed  by  the  union  of  the  two  rows  of 
carpal  hones.  The  line  of  articulation  is  composed  of  three'  distinct  parts — on  the 
outer  side  the  scaphoid  of  the  first  row  articulates  with  the  trapezium  and  the 
trapezoid  of  the  second  row  ;  in  the  middle  the  scaphoid  and  the  semilunar  of  the 
first  row  form  a  cup-shaped  cavity  into  which  the  head  of  the  os  magnum  and  the 
superior  margin  of  the  unciform  of  the  second  row  are  received  ;  on  the  inner 
side  the  cuneiform  of  the  first  row  articulates  with  the  unciform  of  the  second. 
The  two  rows  of  the  carpus  are  held  in  place  by  four  ligaments — the  anterior 
medio-carpal,  the  posterior  medio-carpal,  the  internal  lateral,  and  the  external 
lateral. 

The  anterior  medio-carpal  ligament  connects  the  palmar  surfaces  of  the 
bones  of  the  first  row  with  those  of  the  second.  Most  of  the  fibers  extend  from 
the  first  row  to  the  os  magnum,  others  connect  the  scaphoid  to  the  trapezium 
and  the  trapezoid,  while  the  remaining  ones  pass  from  the  cuneiform  to  the 
unciform. 

The  posterior  medio-carpal  ligament  consists  of  fibers  which  pass  obliquely 
from  the  first  to  the  second  row.  It  is  not  uniform  throughout,  being  stronger  on 
the  ulnar  side. 

16 


•2-\->  SURGICAL    A  ^. \THMY. 

The  external  lateral  ligament  connects  the  sc.-iphoid   \vitli  the  trapezium. 

The  internal  lateral  ligament  connects  tlie  cuneiform  with   the  nnciibrm. 

The  synovial  membrane  of  the  carpus  lines  the  medio-carpal  joint,  ami  sends 
two  prolongations  upward  between  the  scaphoid  and  semilunar  and  the  semilnnar 
and  cuneiform  bones.  It  sends  downward  three  extensions  which  line  the  joints 
of  the  second  row,  the  earpo-metaearpal  joints  of  the  four  inner  inetacarpal  bones, 
and  till'  joints  between  the  bases  of  these  inetacarpal  bones. 

MOVEMENTS  of  the  carpal  joints  are  limited,  to  a  great  extent,  to  the  motions 
of  ilexion  and  extension.  There  is  allowed  a  gliding  motion  which  i.s  antero- 
posterior,  and  a  very  .slight  degree  of  rotation  between  the  articulation  of  the 
os  magnum  with  the  scaphoid  and  the  semilunar. 

BLOOD  SUPPLY. — The  carpal  articulations  are  nourished  by  the  anterior  and 
posterior  carpal  branches  of  the  radial  and  ulnar  arteries,  by  the  anterior  inter- 
osseous,  and  the  recurrent  carpal  brandies  of  the  deep  palmar  arch. 

NEKVK  STPPLY: — Derived  from  the  ulnar,  the  median,  and  the  posterior 
interosseous  nerve. 

DISSECTION. — To  expose  the  articulating  surfaces  of  the  medio-carpal  joint  and 
the  interosseous  ligaments  divide  the  dorsal  and  lateral  ligaments  and  strongly 
ilex  the  hand. 

CAi;?( >-MKTACARPAL  ARTICULATIONS. 

The  articulations  between  the  carpal  and  inetacarpal  bones  may  be  divided 
into  two  sets — the  junction  of  the  four  inner  inetacarpal  bones  with  the  unciform, 
os  magnum,  and  trape/oid  ;  and  the  articulation  of  the  inetacarpal  bone  of  the 
thumb  with  the  trapezium. 

In  the  First  Set  the  metacarpal  bone  of  the  index  finger  articulates  with  the 
trape/oid,  that  of  the  middle  finger  with  the  os  magnum,  and  the  ring  and  little 
lingers  with  the  unciform.  The  ligaments  connecting  the  bones  are  dorsal,  palmar, 
and  interosseous. 

The  dorsal  ligaments  are  stronger  and  more  distinct  than  the  palmar.  They 
connect  the  dorsal  surface  of  the  respective  carpal  bones  with  the  dorsal  surface 
of  the  inetacarpal  bones.  The  inetacarpal  bone  of  the  index  finger  has  two 
fasciculi — one  from  the  trapezium,  the  other  from  the  trape/oid  ;  that  of  the 
middle  finger  has  two — one  from  the  trapezoid  and  one  from  the  os  magnum  ; 
that  of  the  ring  finger  has  two — one  from  the  os  magnum  and  one  from  the 
unciform  ;  that  of  the  little  finger  has  but  one — from  the  unciform. 

The  palmar  ligaments  are  somewhat  similar  to  the  dorsal.  The  metaearpal 
bone  of  the  index  linger  has  one  fasciculus — from  the  trapezium,  under  cover  of 
the  flexor  carpi  radialis ;  that  of  the  middle  finger  has  three — one  from  the  os 


PLATE  LXVI. 


Metacarpal  bone- 


-Metacarpal  bone 


Lateral  process  of  common 
extensor  tendon- 


Synovial  membrane- 
Lateral  ligament- 


-Transverse  metacarpal 
ligament 


Proximal  phalanx- 


Extensor  tendon. 
Lateral  ligament- 


-Proximal  phalanx 


.Anterior  Interphalangeal  ligament 
.Flexor  sublimis  digitorum  tendon 


Lateral  ligament- 
Extensortendon- 


-Anterior  Interphalangeal  ligament 


-Flexor  profundus  dfgitorum  tendon 


METACARPO-PHALANGEAL  AND  INTERPHALANGEAL  LIGAMENTS  (MIDDLE  FINGER). 

244 


JOINTS    OF  THE   UPPER   EXTREMITY. 

magnum,  one  from  the  trapezium,  and  a  third  from  the  imciform  and  the  base  .of 
the  fifth  mcta carpal ;  the  ring  and  little  fingers  have  one  each — from  the  uncifonn. 

The  interosseous  ligament  is  found  only  in  one  part  of  the  joint.  It  connects 
the  adjacent  angles  of  the  unciform  and  os  magnum  with  the  metacarpal  bones  of 
the  middle  and  ring  fingers. 

The  synovial  membrane  is  a  continuation  of  that  lining  the  medio-carpal 
joint.  At  times  there  is  a  separate  synovial  lining  for  the  articulation  of  the  unci- 
form with  the  fourth  and  fifth  metacarpal  bones. 

BLOOD  SUPPLY. — The  carpo-metacarpal  joint  of  the  index  finger  is  nourished 
by  the  radial,  the  metacarpal,  the  dorsalis  indicis,  and  the  radialis  indicis  artery  ; 
of  the  middle  and  ring  fingers,  by  the  anterior  and  posterior  carpal  arches  and 
the  deep  palmar  arch  ;  of  the  little  finger,  by  the  ulnar  artery  and  its  deep 
branch  and,  also,  the  posterior  carpal  arch. 

NERVE  SUPPLY. — From  the  deep  palmar  branch  of  the  ulnar,  from  the 
median  and  posterior  interosseous  nerves. 

The  Second  Set  consists  of  the  articulation  between  the  metacarpal  bone 
of  the  thumb  and  the  trapezium.  But  one  ligament,  the  capsular,  connects  these 
bones. 

The  ligament  is  a  loose  capsule  which  extends  from  the  margin  of  the  articu- 
lar surface  of  the  trapezium  to  that  of  the  metacarpal  bone.  It  is  stronger  on  its 
dorsal  aspect. 

The  synovial  membrane  is  separate  from  that  of  the  carpal  and  the  other 
carpo-metacarpal  joints. 

MOVEMENTS  of  the  carpo-metacarpal  joint  of  the  four  inner  metacarpal  bones 
are  slight ;  that  of  the  little  finger  is  most  free,  followed  by  that  of  the  ring 
finger.  The  articulations  of  the  index  and  middle  fingers  are  almost  immovable. 
The  carpo-metacarpal  joint  of  the  thumb  is  allowed  the  greatest  freedom  of 
motion  by  the  shape  of  the  articulating  surfaces  of  the  bones. 

BLOOD  SUPPLY. — This  joint  is  nourished  by  the  radial,  dorsalis  pollicis,  and 
princeps  pollicis  arteries. 

NERVE  SUPPLY. — From  the  median  nerve. 


THE   INTERMETACARPAL  ARTICULATIONS. 

The  metacarpal  bones  of  the  four  fingers  are  held  together  at  each  end  by 
ligaments.  The  lateral  articular  surfaces,  at  their  carpal  extremities,  are  held  in 
apposition  by  dorsal,  palmar,  and  interosseous  ligaments. 

The  dorsal  and  palmar  ligaments  are  attached  to  the  respective  surfaces  of 
the  bones. 


246  SURGICAL    AXATOMY. 

The  interosseous  ligaments  pass  between  the  lower  margins  of  the  adjacent 
articulating  surface-. 

The  synovial  membranes  of  these  joints  are  extensions  of  the  common 
carpal  synovial  membrane. 

BLOOD  SI:ITLY. — From  twigs  of  the  palmar  and  dorsal  interosseons  arteries. 

NERVE  STI-PLY. — From  the  ulnar  and  posterior  interosseous  nerves. 

The  distal  extremities  or  heads  of  the  four  inner  metaearpal  bones  are  held 
in  place  by  the  transverse  ligament,  which  is  situated  on  the  anterior  or  palmar 
surface.  It  is  a  fibrous  band  consisting  of  three  fasciculi,  which  connect  the 
second  and  third,  the  third  and  fourth,  and  the  fourth  and  fifth  bones.  It 
blends  with  the  glenoid  ligament  of  the  mctacarpo-phalaiigeal  articulations.  The 
interosseous  muscles  pass  behind  it  to  reach  their  points  of  insertion,  while  the 
digital  arteries  and  nerves  and  flexor  tendons  and  lumbrical  muscles  pass  in 
front  of  it. 

The  Metacarpo-phalangeal  Articulations. — The  head  of  each  metaearpal 
bone  is  received  into  a  cup-shaped  cavity  on  the  proximal  end  or  base  of  the  cor- 
responding phalanx.  They  are  held  in  place  by  an  anterior  (glenoid)  and  two 
lateral  ligaments. 

The  anterior  (glenoid)  ligament  is  a  dense,  fibrous  plate  which  is  firmly 
attached  to  the  base  of  the  first  phalanx  and  loosely  attached,  by  areolar  tissue,  to 
the  head  of  the  metaearpal  bone.  It  deepens  the  articular  surface  of  the  base  of 
the  phalanx.  Its  margins  are  continuous  with  the  lateral  ligament,  the  transverse 
metaearpal  ligament,  and  the  fibrous  sheath  of  the  flexor  tendon. 

The  lateral  ligaments  are  strong  short  bands,  situated  on  either  side  of  the 
joint,  that  connect  the  tubercle  and  depression  on  the  side  of  the  head  of  the  meta- 
earpal bone  to  the  base  of  the  phalanx.  Anteriorly  they  are  continuous  with  the 
anterior  ligament  and.  posteriorly,  with  the  expansion  of  the  extensor  tendon. 

The  synovial  membrane  is  very  loose. 

The  posterior  surface  of  the  joint  is  covered  by  an  expansion  of  the  extensor 
tendon,  which  serves  the  purpose  of  a  dorsal  ligament. 

MOVEMENTS  of  these  joints  include  flexion,  extension,  adduction,  and 
abduction. 

BLOOD  SUPPLY. — Derived  from  the  digital  and  palmar  interosseous  arteries. 

NERVE  SUPPLY. — Derived  from  the  digital  nerves. 

The  articulation  between  the  head  of  the  metaearpal  bone  of  the  thumb  and 
the  base  of  the  phalanx  is  different  from  those  of  the  fingers,  on  account  of  the 
shape  of  the  articulating  surfaces.  The  head  of  the  metaearpal  bone  of  the  thumb 
is  wider  than  the  heads  of  the  metaearpal  bones  of  the  fingers,  and  instead  of 
being  rounded,  has  an  irregularly  raised  palmar  edge,  upon  which  are  two  facets 


i>47 


for  sesanioid  bones.  The  ligaments  are  two  lateral  and  a  posterior.  The 
ligaments  are  sliort,  fibrous  hands  which  connect  the  adjacent  ends  of  the  articu- 
lating hones.  The  jin.ffi  i-'nir  ligament  passes  across  I  he  joint  and  connects  the  two 
lateral  ligaments. 

The  sesamoid  bones,  two  in  number,  rest  on  the  facets  on  the  head  of  the 
metacarpal  bone  of  the  thumb,  in  the  tendons  of  the  flexor  brevis  pollicis.  They 
are  connected  by  transverse  libers  which  cover  the  front  of  the  joint. 

BLOOD  SUPPLY.  —  Derived  from  the  princeps  pollicis  and  dorsales  pollicis. 

XKKVK  SUPPLY.  —  Derived  from  the  digital  branches  of  the  median  and  radial 
nerves. 

THE  IXTERPHALAXGEAL  ARTICULATIONS. 

The  ligaments  of  the  interphalangeal  articulations  consist  of  an  anterior 
(gleiioid)  and  two  lateral. 

The  anterior  (glenoid),  like  that  of  the  metacarpo-phalangeal  joint,  is  loosely 
attached  to  the  proximal  bone,  but  very  firmly  to  the  distal.  It  blends  with  the 
lateral  ligaments.  The  flexor  tendons  pass  over  the  anterior  ligament, 

The  two  lateral  ligaments  are  strong  bands  which  connect  the  sides  of  the 
proximal  phalanx  with  the  lateral  aspect  of  the  distal  phalanx. 

Posteriorly,  the  extensor  tendon  covers  the  joint  and  takes  the  place  of 
a  posterior  ligament.  The  tendon  blends  with  the  lateral  ligaments  to  com- 
plete the  capsule  around  the  joint. 

The  synovial  membranes  of  these  joints  are  lax. 

MOVKM  KNTS  of  the  interphalangeal  joints  are  limited  to  extension  and 
tlexion  ;  flexion  being  much  more  free  than  extension.  Lateral  movement  is 
prevented  by  tenseness  of  the  lateral  ligaments. 

BLOOD  SUPPLY.  —  Derived  from  the  collateral  digital  arteries. 

NERVE  SUPPLY.  —  From  the  collateral  digital  nerves. 


DISLOCATIONS. 

It  has  been  shown,  in  the  description  of  the  ligaments  of  the  various  joints, 
that  the  bones  forming  the  articulations  are  so  firmly  held  in  place  that  it  is  almost 
impossible  to  have  a  luxation,  or  dislocation,  without  tearing  one  or  more  of  the 
ligaments.  At  times  the  tiasues  surrounding  the  joint  may  become  so  lax  and  so 
stretched  that  without  rupture  of  any  of  the  ligaments  they  will  allow  a  displace- 
ment of  the  bones  composing  the  joint.  The  muscles  play  a  very  important  part 


IMS  SURGICAL   ANATOMY. 

in  the  reduction  of  lnxation>.  By  manipulating  tlu'  dislocated  nuMiilici1  so  Unit  the 
muscles  will  have  an  opportunity  to  return  to  tlieir  normal  condition  from  the 
Overstretched  state  caused  by  the  luxation,  the  displaced  member  can,  more  easily. 
lie  reduced. 

Dislocations  should  be  reduced  as  so«m  after  the  injury  :is  possible,  because 
after  swelling  and  inflammation  have  developed  reduction  is  more  difficult,  and 
early  reduction  lessens  the  probability  of  subsequent  disability. 

The  clavicle  may  be  dislocated  at  either  end.  Luxations  at  the  sternal 
end  may  be  forward,  forward  and  upward,  forward  and  downward,  or  upward. 
A  backward  displacement  is  rarely,  if  ever,  si-en.  In  complete  luxation  of  the 
sterno-clavicular  joint  it  is  probable  that  the  anterior  and  posterior  sterno-clavicular 
and  the  inlerclavicnlar  ligament  will  be  ruptured.  The  costo-clavieular  ligament 
will  also  stiller  to  a  greater  or  less  extent.  The  interarticular  fibi'o-cartilage  may 
remain  attached  to  either  of  the  bones. 

Dislocation  of  the  clavicle  at  the  acromial  end  is  much  more  frequent  than  at 
the  sternal  end.  In  most  cases  there  is  but  a  partial  dislocation.  The  capsular 
ligament  formed  by  the  superior  and  inferior  aeromio-clavicular  ligaments  is  torn, 
while  the  conoid  and  trapexoid  ligaments  remain  intact  but  are  stretched.  In 
complete  luxation  the  conoid  and  trapezoid  ligaments  are  more  or  less  torn.  The 
trape/.ius  muscle  then  tends  to  pull  the  distal  end  of  the  clavicle  upward,  section 
of  the  libers  of  the  trapezius  often  being  required  to  allow  reduction  to  be 
maintained. 

Dislocations  of  the  humerus  are  very  frequent,  owing  to  the  great  freedom 
of  motion  at  the  shoulder,  the  exposed  position  of  the  joint,  and  because  the  joint 
depends- for  its  strength  chiefly  upon  the  elasticity  and  tonic  contraction  of  the 
surrounding  muscles;  consequently,  when  the  muscles  are  relaxed  and  force  is 
suddenly  applied  to  the  joint  directly  by  a  blow  upon  the  shoulder,  or  indirectly 
by  a  fall  upon  the  hand  or  elbow,  the  head  of  the  humerus  slips  out  of  the  glenoid 
cavity.  Four  varieties  are  usually  described :  Three  anterior — subcoracoid,  sub- 
glenoid,  and  subclavicular  ;  and  one  posterior — the  subspinous. 

In  the  aiitii/fciiniil  /ii.i'iifinn  the  head  of  the  humerus  makes  nts  escape  from  the 
glenoid  cavity  by  tearing  through  the  lower  part  of  the  capsular  ligament.  The 
head  of  the  humerus  is  then  found  in  the  axilla,  resting  upon  the  triangular  part 
of  the  axillary  border  of  the  scapula,  immediately  below  and  a  little  in  front  of  the 
glenoid  cavity  and  between  the  tendon  of  the  subscapularis  and  that  of  the  long 
head  of  the  triceps  muscle.  The  superior  part  of  the  capsule  is  tightly  stretched 
across  the  glenoid  cavity.  In  many  cases  the  tendon  of  the  long  head  of  the 
biceps  will  be  torn.  •  The  muscles  attached  to  the  tuberosities  of  the  humerus 
are  put  on  the  stretch  or  are  lacerated.  Thus  the  supru-spinatus  muscle  is 


PLATE  LXVII, 


DISLOCATED  SHOULDER  AND   NORMAL  SHOULDER. 
249 


DISLOCATIONS   OF  THE   UPPER   EXTREMITY.  251 

stretched  or  lacerated ;  the  inftaspirtatus,  suhscapularis,  and  coraco-brachialis  are 
generally  put  oil  the  stretch  ;  the  deltoid  muscle  is  in  extreme  tension  and  draws 
tlin  elbow  away  from  the  body  ;  the  teres  major  and  the  teres  minor  are  relaxed. 
The  rotundity  of  the  shoulder  is  lost,  and  a  flatness  is  present  owing  to  the 
displacement  of  the  greater  tuberosity,  which  allows  an  undue  prominence  of  the 
acromion  process  to  exist  and  causes  the  formation  of  a  transverse  depression 
below  it.  The  circumflex  nerve,  which  curves  over  the  lower  margin  of  the 
subseapularis  muscle  and  around  the  surgical  neck  of  the  humerus  is  liable  to 
injury,  producing  paralysis  of  the  deltoid.  Atrophy  of  the  deltoid  is  caused  by 
disuse,  as  in  ankylosis  of  the  shoulder-joint;  more  frequently  by  diseases  of  the 
spinal  cord,  as  acute  anterior  polio-myelitis ;  by  ascending  neuritis  of  the  circum- 
flex nerve  usually  due  to  disease  of  the  shoulder-joint  and  causing  paralysis  of 
the  muscles;  and  by  injury  of  the  circumflex  nerve  by  a  blow  or  fracture  of  the 
upper  part  of  the  humerus.  On  account  of  the  relation  of  the  contents  of  the 
axilla  to  the  head  of  the  dislocated  humerus  there  may  be  injury  to  the  nerves 
and  vessels  of  this  space ;  the  axillary  artery  or  vein  may  be  ruptured  ;  the 
brachial  plexus  of  nerves  has  been  stretched  so  much  that  a  partial  paralysis 
followed  the  dislocation.  This  dislocation  and  fracture  of  the  anatomic  neck 
of  the  scapula  are  the  only  injuries  about  the  shoulder  in  which  the  arm  is 
lengthened. 

In  the  aubcoracoid,  the  most  frequent  luxation,  the  head  of  the  bone  escapes 
through  a  tear  in  the  anterior  part  of  the  capsule,  and  rests  below  the  coracoid 
process  upon  the  anterior  surface  of  the  neck  of  the  scapula.  There  is,  generally, 
injury  to  the  coraco-brachialis  and  the  short  head  of  the  biceps,  the  conjoined 
tendon  of  origin  of  which  muscles  will  be  found  to  rest  on  the  anterior  surface  of 
the  head  of  the  bone. 

In  the  subclavicular  luxation  the  head  of  the  bone  escapes  through  a  tear  in 
the  anterior  portion  of  the  capsule,  and  rests  below  the  clavicle  against  the  chest, 
beneath  the  pectoralis  major  and  minor  muscles.  In  both  the  subcoracoid  and 
subclavicular  luxations  the  deltoid  is  greatly  stretched,  and  the  subseapularis  is 
carried  upward,  with  occasional  rupture  of  its  attachment  to  the  lesser  tuberosity 
of  the  humerus.  The  infra-spinatus  and  supra-spinatus  muscles  are  stretched  and, 
at  times,  lacerated.  The  vessels  and.  nerves  of  the  axilla  are  carried  forward  with 
the  head  of  the  humerus ;  the  stretching  of  the  nerves  causes  extreme  pain. 
The  long  head  of  the  biceps  has  been  torn.  The  circumflex  nerve,  which  curves 
over  the  lower  margin  of  the  subseapularis  muscle,  may  be  severely  injured  by 
pressure,  contusion,  or  laceration. 

In  the  subspinous  luxation  the  head  of  the  bone  is  forced  through  a  rent  in 
the  posterior  and  lower  part  of  the  capsule,  and  rests  upon  the  posterior  surface 


SURGICAL    -lY.I'/'O.UT. 

of  the  capsule,  below  the  spine  of  the  scapula  aud  beneath  the  infra-spinatus 
muscle.  The  infra-spinatus  will  he  relaxed,  but  the  supra-spiiiatus  and  snl>- 
scapularis  stivlcheil  or  torn.  The  tendon  of  the  long  head  of  the  hiceps  and 
llie  anterior  tihers  of  the  deltoid  will  he  stretched,  hut  not  ruptured. 

In  all  the  lii.i'iitim/x  of  the  J/cad  of  the  hunierus  the  r<>fniulili/  of  the 
shoulder  will  be  lost,  and  jl<ill<nini/  present,  owing  to  the  displacement  of  the 
greater  tuberosity ;  a  depression  will  he  seen  where  the  greater  tuherosity  is  nor- 
mally found.  The  head  of  the  hone  will  he  found  as  a  swelling  in  the  location  to 
which  it  has  been  displaced.  Flattening  of  the  shoulder  in  dislocation  of  the 
shoulder-joint  must  not  be  mistaken  for  atrophy  of  the  deltoid  muscle.  In  the 
latter  condition  the  mobility  and  position  of  the  head  of  the  hunierus  and  position 
of  the  tuberosities  are  normal. 

In  all  the  forward  or  anterior  luxations  the  elbow  is  carried  away  from  the 
body  by  the  resultant  tension  of  the  deltoid.  In  the  snbspinous  luxation  (posterior) 
the  elbow  is  carried  forward  and  to  the  side  of  the  body  by  the  pectoralis  major 
and  coraco-hrachialis  muscles.  In  the  reduction  of  shoulder-joint  dislocations  the 
axillary  vein  or  artery  may  be  injured,  as  may  also  the  nerves  in  this  locality  : 
therefore,  great  care  must  be  observed  to  avoid  such  an  accident,  especially 
if  the  lesion  has  existed  for  any  time  prior  to  treatment.  The  condition  of  the 
axillary  artery  should  be  determined.  If  the  artery  is  atheromatous  or  included 
in  dense  connective  tissue,  formed  during  the  associated  inflammation,  it  may 
be  ruptured  in  the  attempt  at  reduction.  The  vessel  which  is  more  commonly 
ruptured,  however,  is  the  axillary  vein.  Fixation  of  the  scapula  is  an  important 
adjuvant  in  the  reduction  of  dislocations  of  the  humerus. 

Dislocations  at  the  elbow-joint  may  involve  both  the  radius  and  ulna,  or 
either  hone  separately;  dislocations  of  both  bones  may  be  backward,  forward, 
inward,  or  outward. 

In  the  diagnosis  of  dislocations  at  the  elbow  the  relation  of  the  olecranon 
to  the  condyles  of  the  humerus,  and  the  head  of  the  radius  to  the  external 
condyle,  should  be  determined.  When  the  forearm  is  extended,  the  tip  of  the 
olecranon  is  slightly  above  a  line  drawn  between  the  condyles;  when  the  forearm 
is  flexed  to  a  right  angle,  it  is  below  the  intercondyloid  line ;  and  in  extreme 
flexion  the  olecranon  is  in  a  plane  anterior  to  that  line.  The  olecranon  is  nearer 
to  the  internal  than  to  the  external  condyle;  and  the  distance  between  the  inner 
margin  of  the  olecranon  and  the  internal  condyle  is  merely  sufficient  to  accom- 
modate the  ulnar  nerve.  The  head  of  the  radius  during  pronation  and  supination 
is  felt  rotating  just  below  the  external  condyle  of  the  humerus. 

In  the  backu'ard  luxation  of  both  bones,  the  most  common  dislocation  at  the 
elbow,  their  proximal  extremities  are  carried  so  far  backward  that  the  coronoid 


DISLOCATIONS   OF   THE    UPPER   EXTREMITY.  253 

process  of  the  ulna  rests  in  the  olecranon  fossa  of  the  humerus,  and  the  head  of  the 
radius  lies  behind  the  external  humeral  condyle.  The  hones  are  pulled  upward 
hy  the  triceps  muscle.  The  articulating  surface  of  the  humerus  can  he  plainly  felt 
in  front  of  the  elbow.  The  posterior  and  orbicular  ligaments  do  not  suffer  injury, 
while  the  anterior  and  the  two  lateral  ligaments  will  be  ruptured.  The  tendon  of 
the  biceps  is  pulled  backward  over  the  articulating  surface  of  the  humerus,  and, 
while  tense,  is  seldom  ruptured.  The  brachialis  anticus  will  be  forcibly  stretched. 
The  ulnar  nerve  may  be  painfully  stretched,  on  account  of  its  being  carried 
backward  with  the  ulna.  The  median  nerve,  together  with  the  ulnar  and  inter- 
osseous  vessels,  suffers  from  the  pressure  of  the  projecting  humerus. 

Simple  forward  dislocation  of  the  radius  and  ulna  has  been  said  by  many 
surgeons  to  be  impossible.  They  contend  that  it  is  necessary  to  have  a  fracture  of 
the  olecranon  process  of  the  ulna  in  order  to  allow  the  bones  to  slip  forward.  This 
variety  of  luxation  is  rare.  The  forearm  is  elongated  on  account  of  the  added 
length  of  the  olecranon  process,  which  slips  forward  and  rests  in  front  of  the 
trochlear  surface  of  the  humerus.  There  will  be  a  depression  in  front,  correspond- 
ing to  the  greater  sigmoid  cavity  of  the  ulna.  The  trochlear  surface  of  the 
humerus  will  he  plainly  felt  posteriorly,  with  the  tendon  of  the  triceps  tightly 
stretched  over  it,  unless  this  structure  has  been  ruptured.  The  humeral  condyles 
will  be  very  prominent.  The  posterior  ligament  will  be  ruptured  and  the 
lateral  ligaments  will  be  in  extreme  tension.  When  the  dislocation  is  more 
complete,  the  olecranon  process  of  the  ulna  rests  in  front  of  the  internal  condyle 
of  the  humerus,  and  the  head  of  the  radius  in  the  coronoid  depression  of  the 
humerus. 

In  both  the  backward  and  forward  luxations  of  the  radius  and  ulna  the 
olecranon  process  and  the  external  and  internal  condyles  are  not  in  line. 

The  elbow-joint  is  most  readily  dislocated  backward  when  the  joint  is  in 
incomplete  extension,  for  in  this  position  the  coronoid  process  offers  less  resistance 
to  backward  movement  of  the  upper  end  of  the  ulna,  and  the  olecranon  is  not 
engaged  in  the  olecranon  fossa.  Forward  luxation  is  most  likely  to  occur  when 
the  joint  is  incompletely  flexed,  as  in  this  position  the  olecranon  process  of  the 
ulna  less  firmly  grasps  the  humerus,  and  the  coronoid  process  is  not  engaged  in 
the  coronoid  depression  of  the  humerus. 

Dislocations  forward  or  backward  are  more  common  than  lateral  luxations. 
This  is  explained  by  the  short  antero-posterior  and  long  transverse  diameter  of  the 
joint  and  by  the  weakness  of  the  anterior  and  posterior  ligaments  and  the  greater 
strength  of  the  lateral  ligaments. 

Inward  luxation  (lateral)  is  always  incomplete.  That  it  is  incomplete  is 
probably  due  to  the  fact  that  the  inner  side  of  the  trochlear  surface  of  the  humerus 


SURGICAL   ANATOMY. 

is  somewhat  elevated,  thus  making  it  necessary  for  the  ulna  to  asccinl  an  inclined 
plane.  This  also  accounts  tor  the  intVe<|ueiit  occurrence  of  this  luxation.  The 
median  ridge  of  the  greater  sigmoid  cavity  of  the  ulna  is  forced  over  tin-  inclined 
plane  of  the  troehlea.  The  outer  part  of  the  sigmoid  cavity  rests  on  the  inner 
margin  of  the  troclilea  or  below  the  internal  eondyle.  The  head  of  the  radius 
is  forced  inward  and  rests  against  the  trochlear  space  which  is  normally  occupied 
by  the  sigmoid  cavity  of  the  ulna.  The  ulnar  nerve  is  forcibly  stretched:  this 
may  be  the  cause  of  intense  suffering.  The  internal  lateral  ligament  is  almost 
always  raptured,  while  the  external  lateral,  the  orbicular,  the  anterior,  and  the 
posterior  ligament  are  put  on  the  stretch. 

Outward  luxation  of  both  bones  is  more  frequent  than  inward  luxation, 
on  account  of  the  inclined  plane  formed  by  the  elevated  inner  side  of  the  trochlear 
surface  of  the  humerus.  The  dislocation  is  generally  incomplete,  although  there 
ai'e  on  record  eases  of  complete  outward  luxation  of  both  bones.  In  partial 
outward  dislocation  the  inner  part  of  the  sigmoid  cavity  will  rest  on  the  external 
eondyle  of  the  humerus,  or  the  crest  of  the  sigmoid  cavity  will  occupy  the 
depression  between  the  trochlear  surface  and  the  radial  head  of  the  humerus. 
In  complete  outward  dislocation  the  coronoid  process,  the  olecranon  process,  and 
the  greater  sigmoid  cavity  of  the  ulna  will  be  plainly  felt  lying  to  the  radial 
side  of  the  humerus.  The  internal  eondyle  of  the  humerus  will  be  very 
prominent.  The  head  of  the  radius  will  remain  in  its  normal  relation  to  the 
ulna,  if  the  orbicular  ligament  remains  intact,  or  it  may  be  carried  forward 
or  backward,  if  that  ligament  be  ruptured.  All  of  the  ligaments  of  the  elbow- 
joint  will  be  stretched,  and  some  probably  torn.  The  fibers  of  the  brachialis 
anticus  and  anconeus  muscles  may  be  lacerated.  The  tendons  of  the  biceps  and 
triceps  will  not  be  injured,  but  will  hold  a  more  oblique  position. 

The  head  of  the  radius  may  be  dislocated  forward,  forward  and  outward, 
and  backward.  The  last-named  dislocation  is  very  rare. 

In  the  forward  I</.r</li<>n,  the  most  common,  the  head  of  the  radius  is  generally 
found  upon  the  front  of  the  humerus.  The  anterior  and  external  lateral  ligament > 
are  more  or  less  torn,  and  the  orbicular  ligament  is  either  lacerated  or  so  stretched 
that  it  will  allow  complete  luxation. 

The  head  of  the  radius  may  be  dislocated  forward  by  roughly  jerking  a 
child's  hand,  or  by  lifting  the  child  by  the  hand.  In  this  manner  the  bones 
of  the  forearm  may  be  fractured,  the  deltoid  muscle  torn,  the  shoulder  dislocated, 
or  the  clavicle  fractured. 

In  the  backward  hi  .rut  inn  the  orbicular  ligament  and  the  capsular  ligament 
of  the  elbow  are  both  torn.  The  oblique  ligament  will  either  be  ruptured  or 
stretched.  The  head  of  the  radius  is  found  rotating  behind  the  external  eondyle. 


DISLOCATIONS   OF  THE   UPPER   EXTREMITY.  ->:,r, 

Dislocation  of  the  upper  end  of  the  ulna  alone  is  very  rare.  It  is  almost 
always  associated  with  dislocation  of  the  radius,  or  with  fracture  of  some  of  the 
neighboring  liony  prominences.  The  anatomy  is  similar  to  that  found  in  luxation 
of  both  bones,  with  the  exception  that  the  orbicular  ligament  is  always  torn,  but 
the  head  of  the  radius  holds  its  normal  relation  to  the  capitellum  of  the  humerus. 

Dislocations  of  the  radio-carpal  joint  are  very  rare.  When  they  do  occur, 
they  are,  generally,  complicated  by  fracture  of  the  radius  or  the  styloid  process  of 
the  ulna.  Cases  of  simple  luxation  of  the  joint,  either  backward  or  forward,  do 
occur. 

In  the  Inn- f.-ini  I'd  In. nit  inn  the  posterior  and  lateral  ligaments  are  torn  ;  the 
anterior  ligament  may  remain  intact,  although  it  is  often  lacerated.  The  extensor 
muscles  will  probably  be  found  to  be  torn  from  the  bones  in  the  lower  part  of  the 
forearm,  and  also  displaced.  The  nerves  and  arteries,  in  relation  with  the  joint, 
are  usually  displaced  or  ruptured.  The  radius  and  ulna  will  present  anteriorly, 
while  the  first  row  of  carpal  bones  will  lie  behind  the  bones  of  the  forearm  and 
beneath  the  extensor  tendons.  If  the  luxation  be  compound,  as  it  frequently  is, 
there  will  be  laceration  of  the  tendons  which  cross  the  joint. 

If  the  carpus  be  displaced  forward,  the  reverse  position  of  the  various  bones 
will  be  held,  and  the  flexor  tendons  lacerated  and  displaced.  The  anterior  liga- 
ment will  be  ruptured.  In  both  luxations  the  forearm  is  shortened.  In  the  back- 
ward luxation  the  hand  is  flexed,  while  in  the  forward  it  is  extended. 

In  the  diagnosis  of  dislocation  of  the  wrist-joint  the  relation  of  the  metacarpal 
bone  of  the  thumb  to  the  styloid  process  of  the  radius  should  be  observed.  If  this 
relation  be  normal,  no  dislocation  of  this  joint  can  be  present. 

The  lower  end  of  the  ulna  may  be  dislocated  either  backward  or  forward ; 
this  accident,  uncomplicated,  is  rather  rare.  The  posterior  radio-ulnar  and  the 
internal  lateral  ligament  of  the  wrist-joint  are  torn  in  the  backward  luxation,  and 
the  triangular  fibro-cartilage  is  detached  from  the  ulna.  The  head  of  the  ulna  is 
forced  out  of  its  socket  and  lies  across  the  lower  end  of  the  radius.  In  the  forward 
dislocation  of  the  ulna  the  anterior  radio-ulnar  and  the  internal  lateral  ligament 
are  torn,  and  the  triangular  fibro-cartilage  is  detached  from  the  ulna.  The  head 
of  the  ulna  presents  on  the  anterior  surface  of  the  radius. 

The  separate  carpal  bones  are  rarely,  if  ever,  dislocated,  on  account  of 
the  strong  surrounding  tendons  and  firm  ligaments.  When  any  one  bone  of  the 
carpus  is  luxated,  the  ligaments  holding  it  in  place  will  be  more  or  less  stretched, 
according  to  the  extent  of  the  displacement,  and  the  overlying  or  underlying 
tendons  will  be  somewhat  displaced. 

Luxations  of  the  metacarpal  bones  of  the  fingers  and  thumb  are  also 
very  rare,  and  many  surgeons  are  doubtful  as  to  their  ever  occurring  except 


•-'••><;  SURGICAL    A  \ATOMY. 

as  a  complication.  The  fact  that  they  are  so  firmly  held  in  place  hy  the  anterior 
annular  ligament  and  their  own  ligaments,  as  well  as  hy  the  tle.xor  and  extensor 
tendons,  will  show  why  this  accident  is  BO  rare. 

Dislocations  of  the  phalanges  are  frequent  occurrences,  and  often  lead  to 
permanent  deformity. 

Dislocation  of  the  proximal  phalanx  of  the  thumb  is  an  accident  often  seen, 
and  is,  at  times,  one  of  the  most  difficult  to  reduce.  It  mayoccur  either  as  a  back- 
ward or  a  forward  luxation,  the  former  being  the  more  frequent. 

In  the  Inn-L-iniril  liu-tiUn/i  the  proximal  end  of  the  phalanx  will  present  on  the 
dorsum  of  the  metacarpal  hone  of  the  tlmmh,  and  the  head  of  the  latter  hone  will 
form  a  distinct  projection  on  the  palmar  surface  of  the  thumb.  The  anterior 
ligament  is  torn  and  lies  in  front  of  or  upon  the  head  of  the  metacarpal  hone  :  the 
lateral  ligaments  may  or  may  not  be  lacerated;  (he  tendon  of  the  flexor  longus 
pollicis  is  displaced  to  the  ulnar  side  of  the  head  of  the  metacarpal  hone.  Many 
reasons  have  been  advanced  to  explain  the  frequent  difficulty  in  reduction  of  this 
dislocation  ;  some  of  these  reasons  are  that  the  neck  of  the  metacarpal  hone  is  held 
between  the  two  tendons  of  the  flexor  brevis  pollicis  ;  that  the  muscles  of  the 
thumb  are  so  strong  that  it  is  almost  impossible  to  overcome  them  ;  and  that 
the  neck  of  the  metacarpal  bone  is  held  between  the  lateral  ligaments.  Inter- 
position of  the  anterior  ligament  and  other  parts  of  the  capsule  between  the 
articular  ends  of  the  bones  is  regarded  by  many  surgeons  as  oii'ering  the  chief 
obstacle  to  reduction  of  this  dislocation. 

Forirnnl  Jiij-iit/ini  of  the  proximal  phalanx  of  the  thumb  is  not  very  common. 
The  base  of  the  phalanx  will  present  anteriorly,  with  the  head  of  the  metacarpal 
bone  resting  upon  its  dorsum.  The  lateral  and  anterior  ligaments  will  either 
sustain  severe  stretching  or  he  torn.  This  luxation  is  more  readily  reduced  than 
the  backward  variety. 

In  dislocation  of  the  various  phalanges  of  the  fingers  the  lateral  ligaments 
will  always  be  stretched  and  possibly  torn  ;  the  anterior  ligament  maybe  lacerated, 
and  the  tendons  passing  to  and  over  the  bones  displaced. 


Before  considering  excisions  and  fractures  we  will  consider  the  anatomy  of 
the  long  bones  without  unnecessarily  trespassing  upon  the  domains  of  histology 
and  osteology. 

The  long  bones,  such  as  the  hnmerus,  consist  of  a  shaft  and  two  extremities. 
The  shaft  is  composed  of  an  outer  layer  of  hard,  compact  bone  which  covers  a 


PLATE  LXVIII. 


17 


SKIAGRAPH  OF  FETAL  SKELETON.    BY  M.  i.  WILBERT. 
257 


ANATOMY  OF   THE   LONG    BONES.  259 

layer  of  cancellous  bone  tissue.  The  central  portion  of  the  shaft,  throughout  the 
greater  part  of  its  length,  is  occupied  by  the  marrow  which  fills  the  medullary 
canal.  When  a  bone  is  fractured,  some  of  the  fat  globules  of  the  marrow  may 
enter  torn  veins,  held  open  by  their  adherence  to  the  walls  of  the  bony  channels, 
and  cause  fat  embolism.  In  the  extremities  of  the  bones  the  whole  thickness  of 
the  bone  internal  to  the  compact  bone  is  occupied  by  cancellous  tissue.  The  shaft 
receives  its  nourishment  from  the  periosteum  and  from  the  nutrient  artery  which 
passes  into  the  marrow;  the  extremities  are  nourished  by  the  periosteum  and  the 
articular  arteries.  AVhen,  in  an  amputation,  a  bone  is  divided  above  the  point 
of  entrance  of  the  nutrient  artery,  the  stump  of  the  bone  is  supplied  with  nutri- 
tion through  the  periosteum  and  articular  arteries. 

The  periosteum  is  a  fibrous  membrane  which  invests  the  bones  at  all  parts, 
except  those  portions  which  are  covered  by  articular  cartilage  and  give  attachment 
to  large  tendons.  It  carries  the  blood-vessels  which  nourish  the  external  portion  of 
the  bone.  The  cells  next  to  the  bone  (osteoblasts)  are  capable  of  forming  new 
bone,  therefore  the  deeper  portion  is  called  the  osteo-genetic  layer  of  the  membrane. 
The  outer  layer  is  composed  of  fibrous  and  elastic  tissue,  arranged  chiefly  in  a 
longitudinal  direction.  In  raising  flaps  of  periosteum  it  is  well,  on  account  of  the 
longitudinal  direction  of  the  fibers,  to  make  both  longitudinal  and  transverse  inci- 
sions into  that  membrane,  so  that  it  will  not  split  and  be  stripped  from  the  bone  for 
some  distance. 

It  has  been  demonstrated  that  the  growth  of  a  bone  occurs  in  three  ways :  (1) 
By  means  of  the  osteo-genetic  layer  of  the  periosteum ;  (2)  through  the  epi- 
physeal  cartilage  ;  and  (3)  through  interstitial  deposit  or  deposit  by  the  osteoblasts 
in  the  Haversian  systems.  By  means  of  the  periosteum  and  interstitial  deposit  the 
bone  grows  in  thickness  ;  through  the  epiphyseal  cartilage  and  interstitial  deposit, 
in  length. 

A  bone  increases  in  thickness  chiefly  through  the  osteo-genetic  layer  of  the  peri- 
osteum and  partly  by  interstitial  deposit,  and  in  length  chiefly  through  the  ossifica- 
tion of  successively  developed  layers  of  cells  of  the  epiphyseal  cartilage  which 
connects  the  shaft  with  the  extremities,  and  to  some  extent  by  .interstitial  deposit. 
Therefore,  in  amputations  through  bones  in  young  persons  the  periosteum  should 
not  be  stripped  back  by  pulling  upon  the  flaps  when  the  bone  is  divided,  and  the 
epiphyseal  cartilage  should  be  left  intact  in  excisions  of  joints.  As  a  result  of 
disease  or  injury  of  the  epiphyseal  cartilage  the  epiphysis  sometimes  unites  with 
the  shaft,  and  the  corresponding  bone  of  the  other  side  gradually  becomes  the 
longer  of  the  two.  In  excisions  in  young  persons  under  eighteen  years  of  age  it 
is,  therefore,  important  to  avoid  the  epiphyseal  cartilage,  so  that  the  limb  may  grow 
to  its  full  length.  Occasionally,  after  a  slight  traumatism  the  osteo-genetic  layer 


•2W  xrildH'AL    AXATOMl'. 

of  the  periosteum  becomes  locally  active,  and  an  cxostosis  develops.  In  acute 
suppnrative  periostitis  an  early  incision  down  to  the  hone  i<  required  to  allow  the 
pus  to  escape,  for  if  drainage  is  not  provided,  the  periosteum  is  floated  from  the 
shaft  of  the  bone  from  one  epiphyseal  line  to  the  other,  and  the  whole  shaft  dies 
or  undergoes  necrosis.  The  termination  of  the  periosteum  at  the  line  of  attach- 
ment of  the  ligaments,  and  the  five  and  separate  supply  of  blood  to  the  epiphyses 
through  the  articular  arteries,  minimize  the  danger  that  the  process  will  extend 
into  the  joints.  This  is  fortunate,  as  involvement  of  the  joints  would  probably 
necessitate  amputation. 


EXCISIONS. 

Excisions  may  be  divided  into  excisions  of  bones  and  excisions  of  joints. 
Bones  are  usually  excised  for  ununited  fracture  and  malignant  growth,  and  joints 
for  disease  and  injury  and  for  the  results  of  disease  and  injury.  Excision  of  a  bone 
implies  either  removal  of  a  portion  or  of  the  whole  bone.  The  injuries  in  which 
excision  of  a  joint  may  be  demanded  are  fractures  extending  into  joints,  especially 
if  compound;  gunshot  wounds  of  the  joint  or  of  the  articular  ends  of  the  bones 
entering  into  the  joint ;  and  compound  dislocations.  The  disease  requiring  exci- 
sion is  usually  tubercular  in  character.  The  operation  is  performed  to  shorten 
the  length  of  time  necessary  for  recovery,  thereby  shortening  the  convalescence  of 
the  patient  to  a  few  weeks  instead  of  allowing  the  disease  to  exist  for  months  or 
years  with  an  uncertain  result.  Where  the  patient  is  becoming  weaker  as  a  result 
of  pain  and  persistence  of  the  disease,  the  operation  is  performed  to  save  life.  One 
of  the  results  of  disease  or  injury  to  relieve  which  excision  is  performed  is  ankylosis 
of  the  joint  in  a  bad  position.  All  of  the  diseased  (issue  should  be  removed  so 
that  a  good  result  will  be  assured.  In  the  upper  extremity  the  best  result  is 
obtained  by  preserving  mobility  through  the  formation  of  a  false  joint.  In  the 
lower  extremity  ankylosis  is  more  desirable  than  a  false  joint,  as  the  latter  would 
not  give  certain  support  to  the  superimposed  weight. 

Conditions  for  which  excisions  are  done  in  early  life  require  amputation  later 
in  life,  especially  if  the  disease  involves  a  large  joint. 

In  excision  of  the  clavicle  an  incision  is  carried  along  the  whole  length  of 
the  bone,  from  its  sternal  to  its  acromial  end.  The  incision  should  be  carried 
down  to  the  bone,  and  will  sever  skin,  superficial  fascia,  twigs  from  the  acromio- 
thoracic  and  supra-scapular  arteries,  jugulo-cephalic  vein  when  present,  descending 
branches  of  the  cervical  plexus,  and  the  platysma  myoides  muscle.  The  perios- 
teum should  be  divided  the  whole  length  of  the  bone,  and  stripped  from  it,  first 


OF   THE    I'PPEH    EXTREMITY.  261 

below  and  then  above.  I"  stripping  oil'  the  periosteum  sever  the  attachments  of 
the  sterno-niiistoitl,  pcctoralis  major,  trape/ius,  and  deltoid  muscles,  and  the  attach- 
ment of  the  .interior  Inver  of  the  costo-coracoid  membrane.  Next  cut  through  the 
ligaments  of  the  acromio-clavicular  articulation,  superior  and  inferior  acromio- 
clavieular  ligaments,  ami  the  interarticular  fibro-cartilage,  when  the  acrmnial  end 
of  the  bone  should  he  raised  and  the  structures  attached  to  its  under  surface 
divided — namely,  the  coraco-clavicular  ligament,  the  subclavins  muscle  with  the 
posterior  layer  of  the  costo-coracoid  membrane,  and  the  costo-clavicular  (rhomboid) 
ligament.  Next  detach  the  bone  from  the  opposite  clavicle  and  sternum  by  divid- 
ing the  interclavicular  ligament,  the  anterior  and  posterior  sterno-clavicular 
ligaments,  and  the  interarticular  fibro-cartilage.  In  separating  the  clavicle  from 
the  underlying  structures  care  must  be  taken  to  avoid  injuring  the  subclavian 
vessels  and  brachial  plexus. 

In  sareomatous  tumors  of  the  clavicle  there  will  be  found  many  additional 
vessels,  which  make  the  excision  more  difficult.  If  the  subelavius  muscle  remain 
intact,  it  may  be  taken  as  a  guide  to  the  subclavian  vessels  which  lie  beneath  it. 

Excision  of  the  shoulder-joint  is  required  for  disease  of  the  joint,  caries  of 
the  head  of  the  humerus,  and  disease  of  the  cartilage.  As  the  glenoid  cavity 
quickly  recovers  after  the  head  of  the  bone  is  excised,  the  glenoid  fossa  need  not 
be  removed.  Excision  may  also  be  necessary  in  the  treatment  of  injuries  such  as 
compound  fracture  and  gunshot  wounds  ;  and  sometimes  the  results  of  injury  or 
disease  require  excision  of  the  head  of  the  humerus.  Ankylosis  of  this  joint 
seldom  demands  excision,  because  the  weight  of  the  arm  causes  fixation  in 
the  best  position, — with  the  arm  at  the  side, — and  the  mobility  of  the  scapula 
largely  compensates  for  fixation  in  the  shoulder-joint,  and  the  utility  of  the 
limb  after  excision  may  not  be  any  greater  than  after  the  occurrence  of 
ankylosis. 

Excision  of  the  shoulder. — Tn  excision  of  the  head  of  the  humeniB  an  incision 
is  carried  from  the  acromion  process  for  about  five  inches  down  the  arm  in  the  line 
of  the  humerus.  The  incision  should  be  made  down  to  the  bone,  dividing  in  its 
course  the  skin,  superficial  fascia,  twigs  from  the  acromio-thoracie,  anterior  and  pos- 
terior circumflex  vessels,  acromial  branches  of  the  cervical  plexus  of  nerves,  the  deep 
fascia,  the  fibers  of  the  deltoid  muscle,  and  the  trunk  of  the  anterior  circumflex 
artery  and  vein.  The  capsular  ligament,  is  opened  and  the  supra-spinatus,  infra- 
spinatus,  and  teres  minor  muscles  severed  from  their  attachment  to  the  greater 
tuberosity,  and  the  subscapularis  from  the  lesser  tuberosity.  These  muscles  should 
be  detached  close  to  their  insertions  into  the  tuberosities.  The  long  head  of  the 
biceps  must  be  dissected  from  its  groove  and  pushed  to  one  side.  The  coraco- 
humeral  and  capsular  ligaments  are  then  divided  and  the  head  of  the  humerus 


•2f>-2  SfJiGICAL  ANATOMY. 

protruded  from  the  glenoid  cavity  by  carrying  the  arm  in  front  of  the  body  ami 
pushing  it  upward.  The  diseased  portion  of  the  bone  can  then  be  removed  with- 
out injury  to  the  posterior  circumflex  vessels  and  circumflex  nerve  and  the  struc- 
tures in  the  axilla.  At  times  it  may  be  necessary  to  detach  the  head  of  the  bone 
from  the  shaft  while  it  remains  in  the  glenoid  cavity.  In  such  eases  a  broad  strip 
of  metal  or  horn  should  be  passed  between  the  neck  of  the  bone  and  the  axillary 
structures,  in  order  to  prevent  injury  to  the  latter. 

Excision  in  the  continuity  of  the  humerus. — In  excising  a  portion  of  the 
shaft  of  the  liumerus  the  incision  should  be  made  on  the  outer  aspect  of  the 
arm,  in  the  sulcus  between  the  biceps  in  front  and  the  triceps  behind.  The  skin, 
superficial  fascia,  twigs  of  the  upper  and  lower  cutaneous  branches  of  the 
circumHex  nerve,  twigs  from  the  anterior  and  posterior  circumflex  and  superior 
profunda  vessels,  the  deep  fascia,  and  the  periosteum  will  be  severed.  The  cephalic 
vein  is  avoided.  The  incision  should  be  made  as  long  as  necessary,  but  in  carrying 
it  downward,  care  should  be  taken  to  keep  close  to  the  outer  border  of  the  biceps. 
In  the  lower  part  of  the  arm  it  is  necessary  to  avoid  the  musculo-spiral  nerve, 
which  lies  between  the  brachialis  anticus  and  supinator  longus  muscles.  The 
periosteum  should  be  separated  from  the  bone,  and  as  much  as  necessary  of  the 
humerus  removed.  There  will  be  but  little  bleeding. 

Excision  of  the  elbow-joint  is  performed  for  disease  of  that  joint,  as  tuber- 
cular arthritis ;  injury,  as  compound  dislocation,  compound  and  comminuted 
fractures  ;  and  the  results  of  disease,  as  ankylosis  in  a  bad  position.  Ankylosis  of 
this  joint  causes  considerable  disability  ;  therefore,  in  treating  disease  of  the  joint 
it  is  most  important  to  preserve  its  mobility. 

Excision  of  the  elbow. — With  the  forearm  pronated  and  slightly  flexed,  a 
longitudinal  incision  about  four  inches  in  length  is  carried  over  the  joint,  the  middle 
of  the  incision  being  directly  over  the  olecranon  process  of  the  ulna.  The  incision 
severs  the  skin,  superficial  fascia,  twigs  of  the  inferior  external  cutaneous  branch 
of  the  musculo-spiral  nerve,  twigs  of  the  lesser  internal  cutaneous  nerve,  branches  of 
the  inferior  profunda,  anastomotica  magna,  interosseous  and  posterior  ulnar  recur- 
rent vessels,  and  the  deep  fascia.  This  exposes  the  tendon  of  the  triceps,  which 
should  be  split  longitudinally  down  to  the  bone.  The  outer  half  of  the  triceps,  its 
aponeurotic  expansion,  and  the  anconeus  muscle  should  then  be  carefully  pushed 
to  one  side.  The  internal  part  of  the  triceps  should  next  be  lifted.  In  doing  this 
care  must  be  taken  not  to  injure  the  ulnar  nerve,  which  lies  in  the  groove  between 
the  internal  condyle  of  the  humerus  and  the  olecranon.  The  nerve  is  here 
covered  by  a  dense  membrane,  which  should  be  incised,  when  the  nerve  can  be 
pulled  to  one  side.  Now  remove  the  olecranon  with  the  bone  forceps.  The 
internal  and  external  lateral  ligaments  can  then  be  severed,  and  the  ends  of 


EXCISIONS   OF  THE   UPPER   EXTIIKMITY.  263 

the  bones  protruded  through  the  wound  by  sharply  flexing  the  forearm  and 
separating  the  periosteum  from  (lie  bones  with  the  soft  parts  attached.  A  spatula, 
may  no\v  he  passed  between  the  anterior  surfaces  of  the  hones  and  the  struetures 
in  front  of  the  elhow-joint,  and  a.s  much  hone  removed  as  is  necessary.  ]f  )><>>- 
slide,  it  is  advisalde  to  remove  only  the  articulating  surface  of  the  humerus,  ihe 
(decranon  process  as  low  as  the  coronoid  process,  and  the  head  and  neck  of  the 
radius  ahove  the  tuhercle.  This  will  allow  the  hrachialis  anticus  and  biceps 
muscles  to  remain  intact. 

After  this  operation  for  disease  ankylosis  is  likely  to  occur,  consequently  the 
amount  of  hone  removed  must  not  he  too  small,  and  passive  motion  should  he 
practised  after  ten  days.  After  excision  for  injury  a  flail-like  joint  is  a  result  more 
likely  than  ankylosis,  and  the  part  must  he  kept  steady  hy  a  splint,  which  should 
have  a  hinge  at  the  clhow  so  that  passive  motion  may  he  practised  without 
laterally  moving  the  joint.  Passive  motion  should  at  first  consist  merely  of  a 
change  in  the  position  of  the  forearm,  which  should  lie  flexed  during  the  day  and 
extended  at  night.  Later,  the  movements  may  he  more  frequently  and  freely 
performed,  and  Stipulation  and  pronation  may  he  practised. 

Excision  of  the  bones  of  the  forearm. — In  excising  the  ulna,  or  a  portion 
thereof,  the  incision  should  be  carried  along  the  posterior  or  subcutaneous  border 
of  the  bone,  between  the  extensor  carpi  ulnaris  and  flexor  carpi  ulnaris.  The 
skin,  superficial  fascia,  a  few  small  vessels  and  nerves,  and  generally  the  posterior 
branch  of  the  internal  cutaneous  nerve  will  be  severed.  After  incising  the  deep 
fascia,  the  periosteum  is  divided  and  separated  from  the  bone  as  far  as  necessary, 
carrying  with  it  the  soft  parts.  The  interosseous  membrane,  is  incised  along  the 
radial  side  of  the  bone.  The  bone  can  then  be  divided  with  bone  forceps  or  with 
a  metacarpal  or  chain  saw,  and  removed. 

In  excision  of  the  radius,  or  a  part  of  it,  the  incision  should  be  made  along 
the  outer  side  of  the  bone,  between  the  supinator  longus  and  the  extensor  carpi 
radialis  longior,  taking  advantage  of  the  position  of  the  radial  nerve  in  locating  the 
interval  between  the  tendons  of  the  respective  muscles.  The  skin,  the  superficial 
fascia,  a  few  small  vessels  and  nerves,  the-  deep  fascia,  and  the  periosteum  will 
be  severed.  The  periosteum  is  separated  from  the  radius  as  far  as  necessary ; 
the  insertion  of  the  supinator  longus  at  the  lower  end  of  the  bone  and  that  of  the 
pronator  radii  teres  at  the  middle  of  the  bone  being  detached  with  the  periosteum. 
The  interosseous  membrane,  and  at  times  the  orbicular  ligament,  must  be  detached 
from  the  ulnar  side  of  the  bone,  which  can  then  be  removed  either  with  a  powerful 
pair  of  bone  forceps  or  the  chain  saw. 

Excision  of  the  radio-carpal  joint. — Excision  of  the  wrist-joint  is  usually  per- 
formed for  disease,  such  as  caries,  and  rarely  for  injury,  as  compound  fracture, 


•2i\-\  SURGICAL    A \ATUMY. 

compound  dislocation,  or  gunshot  wounds.  It' an  excision  is  performed  for  disc 
it  is  usually  necessary  to  remove  the  end-  of  the  radius  and  ulna,  the  carpus,  and 
the  l>ases  of  the  nu'tacarpal  hones,  so  as  to  include  all  diseased  hone.  Total  excision 
of  this  joint,  including  the  carpal  hones  and  the  hases  of  the  nietaearpal  hones,  is 
seldom  necessary.  !>y  placing  the  part  at  rest  and  improving  the  general  health 
the  disease  may  usually  he  arrested  without  operation  and  a  useful  hand  preserved. 
Passive'  motion  of  the  lingers  must  he  practised  early  to  obtain  the  best  possible 
result.  In  excising  the  wrist-joint  two  incisions  should  be  made:  one  along  the 
radius,  extending  from  a  point  about  two  inches  above  the  styloid  process  of  the 
radius  to  the  middle  of  the  metacarpal  bone  of  the  thumb;  and  another  along 
the  ulna,  from  a  point  about  two  inches  above  the  styloid  process  of  the  ulna  to 
the  middle  of  the  metacarpal  bone  of  the  little  finger.  The  radial  incision  severs 
the  skin  and  superficial  fascia,  twigs  of  the  musculo-eutancous  and  radial  nerves, 
small  branches  of  the  radial  artery,  some  superficial  veins,  and  the  dee])  fascia. 
(I real  care  must  be  taken  not  to  injure  the  radial  artery,  which  lies  in  front  of  the 
lower  end  of  the  radius  and  upon  the  external  lateral  ligament  of  the  wrist-joint. 
The  radial  incision  passes  between  (lie  tendons  of  the  extensor  ossis  metacarpi 
pollicis  and  extensor  primi  internodii  pollicis.  The  nlnar  incision  divides  the 
skin  and  superficial  fascia,  twigs  of  the  internal  cutaneous  nerve,  small  cutaneous 
branches  of  the  ulnar  artery,  some  superficial  veins,  and  the  deep  fascia.  The 
tendons  and  soft  parts  are  to  be  carefully  dissected  from  the  posterior  surface  of  the 
carpus,  radius,  and  ulna.  The  radial  artery  is  now  displaced,  and  held  aside  with 
a  retractor.  A  sharp-pointed  bistoury  is  entered  on  each  side  in  front  of  the  radius 
and  ulna,  and  the  soft  parts  separated  from  both  bones  by  currying  the  knife 
downward.  As  the  knife  passes  over  the  carpus  it  will  come  in  contact  with  the 
pisiform  bone,  which  lies  on  the  ulnar  side  of  the  forearm  ;  this  bone  should  be 
removed  with  a  pair  of  bone  force] is.  The  lateral  ligaments  are  next  divided,  the 
ulna  and  radius  drawn  out  on  their  respective  sides,  and  the  articulating  surfaces 
removed.  A  blunt-pointed  bistoury  is  used  to  divide  the  dorsal  ligaments  between 
the  two  rows  of  carpal  bones,  and  the  upper  row  is  removed  with  the  sequestrum 
forceps.  If  necessary,  all  the  bones  of  the  carpus  may  be  removed  in  this  manner. 
As  the  curpo-metacarpal  articulations,  are  reached,  great  care  must  be  observed 
not  to  injure  the  deep  palmar  arch.  In  this  operation  there  is  but  little  danger  of 
wounding  the  radial  and  ulnar  arteries,  if  the  proper  amount  of  care  be  exercised. 
In  excising  a  metacarpal  bone  the  incision  should  be  made  over  the  dorsal 
aspect  of  the  bone.  The  skin  and  superficial  fascia  will  be  severed,  together  with 
branches  of  the  radial  and  ulnar  arteries  and  superficial  veins,  branches  of  the 
dorsal  cutaneous  branch  of  the  ulnar  nerve  over  the  metacarpal  bone  of  the  little 
and  the  ring  finger,  and  branches  of  the  radial  nerve  over  the  metacarpal  bone 


EXCISIONS   OF  THE   UPPER   EXTREMITY.  265 

of  the  middle  and  the  index  finger.  The  deep  fascia  is  cut,  and  care  must  be 
taken  to  avoid  injuring  the  extensor  tendons ;  these  must  be  pushed  to  one  side, 
and  the  periosteum  divided.  If  the  head  of  the  bone  is  to  be  removed,  the  meta- 
carpo-phalangeal  joint  must  be  opened  by  cutting  through  one  of  the  lateral  expan- 
sions of  the  extensor  tendon,  raising  the  tendon,  and  dividing  the  lateral  ligaments 
and  the  transverse  melacarpal  ligament ;  the  bone  is  then  elevated.  The  interossc<  >ns 
muscles  must  be  separated  from  the  bone  with  the  periosteum,  and  the  bone  freed 
from  all  surrounding  structures.  As  much  of  the  metacarpal  bone  as  is  diseased 
can  then  be  removed  with  the  forceps.  Care  must  be  taken  not  to  injure  the  deep 
palmar  arch  when  removing  the  structures  from  the  palmar  surface  of  the  bone. 
If  the  entire  bone  be  removed,  the  carpo-metacarpal  ligaments  must  be  severed. 

In  excision  of  the  metacarpal  bone  of  the  thumb  the  incision  should  be 
made  on  the  line  between  the  dorsal  and  palmar  surfaces.  Skin,  fascia1,  branches 
of  the  radial  artery,  superficial  veins,  and  branches  of  the  radial  nerve  will  be 
severed,  yet  with  care  the  branch  of  the  radial  nerve  supplying  the  outer  side  of 
the  thumb  need  not  be  divided.  The  incision  reaches  the  bone  by  passing  along 
the  palmar  side  of  the  tendon  of  the  extensor  primi  internodii  pollicis.  The 
soft  structures  with  the  periosteum  are  separated  from  the  bone  on  the  palmar 
and  dorsal  surfaces,  and  the  ligaments  of  the  carpo-metacarpal  and  metacarpo- 
phalangeal  joints  severed. 

In  excising  the  articulating  surfaces  of  the  phalanges  the  incision  should 
be  made  over  the  dorsal  aspect  of  the  respective  joints  at  the  side  of  the  extensor 
tendon,  and  should  extend  from  the  proximal  side  of  the  joint  to  the  middle  of  the 
phalanx  to  be  removed.  The  incision  is  made  parallel  with  the  extensor  tendon, 
which  is  pushed  to  one  side  as  soon  as  it  has  been  exposed.  The  extensor  tendon 
is  raised,  the  lateral  ligaments  are  severed,  the  ends  of  the  bones  are  elevated,  and 
as  much  bone  as  necessary  removed  with  the  bone  forceps. 

In  excising  the  last  phalanx  the  incision  may  be  made  along  the  palmar 
surface  of  the  finger,  or  around  the  end  of  the  finger.  In  the  former  case  the 
soft  parts  are  stripped  from  the  sides  of  the  bone,  and  in  the  latter  from  the  dorsal 
and  palmar  aspects.  The  bone  is  then  grasped  with  the  bone  forceps  and  twisted 
on  its  long  axis  so  as  to  facilitate  the  division  of  the  two  lateral  ligaments  and 
of  the  flexor  and  extensor  tendons.  It  is  better  to  leave  the  soft  parts  in  place 
than  to  remove  part  of  them  with  the  bone.  If  the  base  of  the  phalanx  is  not 
much  diseased,  it  is  better  not  to  remove  it,  on  account  of  the  attachment  of  the 
tendons. 


•2C,C,  VnuiH'Al.   ANATOMY. 

Development  of  the  Bones  of  the  Upper  Extremity. — The  time  <>f  union  of 
the  various  centers  of  ossification  in  the  bones  of  the  body  plays  an  important  part 
in  the  diagnosis  and  treatment  of  the  various  fractures  which  occur.  This  is 
especially  so  when  the  fracture  is  located  near  one  of  the  epiphyseal  ends  of  the 
bone. 

The  clavicle  lias  two  centers  of  ossification — one  for  the  shaft,  and  one  for  the 
sternal  end.  Ossification  in  the  shaft  begins  about  the  sixth  week  of  fetal  life. 
The  clavicle  is  the  first  bone  in  the  body  to  show  signs  of  ossification.  About  the 
nineteenth  year  an  epiphysis  appears  at  the  sternal  end,  and  subsequently  unites 
with  the  remainder  of  the  bone. 

The  scapula  has  seven  centers  of  ossification — one  for  the  body,  two  for  the 
coracoid  process,  two  for  the  acromion,  one  for  the  posterior  border,  and  one  for  the 
inferior  angle.  At  birth  the  body  of  the  scapula  is  the  only  part  which  is  ossified. 
The  center  for  the  middle  of  the  coracoid  process  appears  in  the  first  year.  The 
other  centers  appear  in  the  fifteenth  or  sixteenth  year,  when  the  coracoid  process 
joins  the  body  of  the  bone.  These  epipliyses  join  and  unite  with  'the  body  of  the 
bone  between  the  twenty-second  and  twenty-fifth  years. 

An  ununited  epiphysis  of  the  acromion  may  be  mistaken  for  an  ununited 
fracture.  The  former  condition  is  recognized  by  the  presence  of  an  ununited 
epiphysis  upon  the  uninjured  side  also,  whereas  ununited  fracture  of  the  acromion 
is  almost  invariably  unilateral. 

The  humerus  has  seven  centers  of  ossification — one  for  the  shaft,  one  for  the 
head,  one  for  the  greater  tuberosity,  one  for  the  capitellum,  one  for  the  internal 
condyle,  one  for  the  trochlea,  and  one  for  the  external  condyle,  and,  generally,  one 
for  the  lesser  tuberosity.  These  centers  appear  at  different  periods,  and  unite, 
as  a  rule,  in  the  reverse  order  of  their  appearance.  About  the  fifth  year  the 
centers  for  the  head  and  tuberosities  coalesce  ;  the  union  of  this  epiphysis  to  the 
shaft  does  not  take  place,  however,  until  about  the  twentieth  year.  The  centers 
for  the  external  condyle,  capitellum,  and  trochlea  coalesce  and  unite  with  the  shaft 
in  the  seventeenth  year.  The  center  for  the  internal  condyle  forms  a  separate 
epiphysis,  which  joins  the  shaft  during  the  eighteenth  year.  From  this  it  can  be 
seen  that  there  may  be  separation  of  the  upper  epiphyses  as  late  as  the  twentieth 
year,  and  of  the  lower  ones  as  late  as  the  sixteenth  to  the  eighteenth  year:  In 
all  epiphyseal  fractures  in  young  children  it  is  to  be  remembered  that  consid- 
erable shortening  may  follow,  as  the  bone  may  fail  to  increase  in  length  owing  to 
injury  to  the  epiphysis. 

The  radius  has  three  centers  of  ossification — one  for  the  shaft  and  one  for 
each  end.  The  upper  end  unites  during  the  seventeenth  year,  the  lower  during 
the  nineteenth.  ' 


PLATE  LXIX, 

EisplacEmEntin  FracturEnfthE  middlEoffhE  Davids. 


Sferno-delda-mastoid. 


\5ubcl wiu s,  Trff/jpzius  3 nit 
}  Rftmitboidei. 

[Perforates  mBJrmi 
i"  \Lafis5ifTJus  dorsi. 

\WeightoMrm 
\antl  Shou/der. 


Frdcfi/re  of  Anatomies  I  Nsck  of  E cap u la, 


268 


FI;. \rruRES  OF  THE  UTTER  EXTREMITY. 

The  ulna  lias   three  (.'(.'liters — one  fur   (lie  shaft  and  coronoid  process,  oiu 
the  oleeranon,  and  one  tor  the  lower  (Mid.     The  lower  end  unites  to  the  shaft  ahout 
the  eighteenth  year,  and  the  oleeranon  center,  although   it  does  not  begin  ossifica- 
tion before  the  eighth,  unites  to  the  shaft  about  the  sixteenth  year. 

The  carpal  bones  each  have  but  a  single  center  of  ossification,  and  these 
uppeur  after  birth,  at  different  periods. 

The  metacarpal  bones  have  two  centers — the  metacarpal  bones  of  the  fingers 
have  a  center  for  the  shaft  and  proximal  end,  and  another  for  the  distal  end  ;  the 
metacarpal  bone  of  the  thumb  has  a  center  for  the  shaft  and  distal  end,  and 
another  for  the  proximal  end.  These  centers  are  united  about  the  twentieth  year. 

Each  phalanx  has  two  centers — one  for  the  shaft  and  distal  end,  the  other  for 
the  proximal  end.  They  unite  about  the  twentieth  year. 


FRACTURES. 

The  treatment  of  fractures  aims :  (1)  To  return  the  parts  to  their  normal 
relations ;  (2)  to  continuously  keep  the  fragments  and  their  ends  steady,  this 
requiring  a  splint,  or  other  stiff  dressing,  which  extends  throughout  the  length  of 
the  fragments  and  beyond  joints  moved  by  muscles  attached  to  the  fragments ; 
(3)  to  retain  the  function  of  joints  or  tendons  in  close  proximity  by  passive  move- 
ment practised  as  soon  as  union  is  sufficiently  firm. 

Fracture  of  the  clavicle  is  very  frequent  because  it  holds  an  exposed  position 
and  is  the  only  bony  connection  between  the  upper  extremity  and  the  trunk.  As 
about  one-half  of  these  fractures  occur  in  children  under  five  years  of  age,  green- 
stick  fracture  of  this  bone  is  common.  In  this  form  of  fracture  there  may  be  little 
displacement,  and  the  true  condition  may  not  be  detected  until  callus  forms  and 
a  swelling  is  produced.  If  a  child  has  fallen  and  cries  constantly,  the  clavicle 
should  be  carefully  examined. 

In  comminuted  fracture  of  the  clavicle  there  is  danger  that  the  subclavian 
vein,  subclavian  artery,  or  brachial  plexus  may  be  injured.  These  structures  are 
protected  by  the  intervening  subclavius  muscle  and  prevertebral  fascia,  and  there- 
fore this  complication  is  rare.  If  the  vein  or  the  artery  be  torn,  the  blood  gravi- 
tates to  the  axilla  through  its  apex,  and  the  resulting  condition  is  a  traumatic 
aneurysm.  If  the  brachial  plexus  be  injured,  there  will  be  motor  and  sensory 
disturbances  in  the  upper  extremity.  Of  these  three  structures  the  vein  is  most 
likely  to  be  injured  because  of  its  closer  relation  to  the  bone  and  the  thinness  of 
its  walls.  A  traumatic  aneurysm  of  the  axilla  has  been  mistaken  for  an  abscess. 


270  SURGICAL  ANATOMY. 

Fractures  of  the  claviele  generally  occur  near  the  outer  end  of  the  middle 
third.  The  reasons  for  the  greater  frequency  of  fractures  in  this  position  are  that 
the  hone  at  this  situation  is  smaller  and  consequently  weaker,  and  begins  to  bend 
forward  and  derives  less  support  from  the  muscles  and  ligaments.  The  deformity 
in  fracture  of  the  middle  third  of  the  clavicle  is  displacement  of  the  inner  frag- 
ment upward,  and  of  the  outer  fragment  downward  and  inward.  The  inner 
fragment  is  drawn  upward  by  the  sterno-cleido-mastoid.  The  outer  fragment  is 
drawn  downward  by  the  weight  of  the  arm  and  shoulder  ;  downward  and  inward 
by  the  pectoralis  major,  the  pectoralis  minor,  and  the  latissimus  dorsi ;  inward  by 
the  subclavius,  trapezius,  and  rhomboidei  muscles. 

In  displacement  of  the  inner  fragment  upward  the  action  of  the  sterno-cleido- 
mastoid  is  antagonized  by  the  rhomboid  ligament,  the  clavicular  portion  of  the 
pectoralis  major,  and  the  inner  fibers  of  the  subclavius  muscle. 

The  clavicular  fibers  of  the  trapezius  antagonize  the  downward  displacement 
of  the  outer  fragment,  and  the  serratus  magnus  its  inward  displacement. 

Fractures  of  the  scapula  are  uncommon,  only  one  per  cent,  of  all  fractures 
occurring  in  this  bone.  This  is  due  to  the  free  mobility  of  the  bone  and  to  its  pro- 
tection by  overlying  muscles.  Fractures  may  involve  any  portion  of  the  bone. 
They  are  usually  produced  by  direct  violence,  but  may  be  caused  by  muscular 
action  or  by  indirect  violence,  as  a  fall  upon  the  arm.  Fractures  of  the  body  of 
the  scapula  not  involving  the  spine  of  the  bone  are  detected  with  difficulty,  because 
of  the  thickness  of  the  overlying  muscles ;  whereas  those  of  the  spine  and  acro- 
mion  are  readily  detected  because  of  their  superficial  position.  Fracture  of  the 
anatomic  neck  of  the  scapula,  which  is  external  to  the  coracoid  process,  is  so  rare 
that  but  one  case  has  been  recorded.  This  condition  simulates  subglenoid  dislo- 
cation, in  that  the  arm  is  lengthened  as  the  arm  and  glenoid  cavity  drop  down- 
ward. It  is  readily  differentiated  from  subglenoid  dislocation  by  raising  the  arm, 
when  crepitus  may  perhaps  be  elicited.  As  soon  as  support  of  the  arm  is  with- 
drawn, the  arm  again  lengthens.  In  fracture  of  the  anatomic  neck  of  the  scapula, 
injury  of  or  pressure  upon  the  axillary  vessels  and  brachial  plexus  is  almost  certain 
to  occur.  In  fracture  of  the  surgical  neck  of  the  scapula  the  glenoid  cavity  and  arm 
are  prevented  from  dropping  downward  by  the  attachment  of  the  coracoid  process 
to  the  clavicle  by  the  coraco-acromial  ligament,  unless  the  latter  is  torn.  Fractures 
of  the  spine  and  acromion  are  detected  by  tracing  these  subcutaneous  processes  with 
the  finger.  Most  of  the  recorded  fractures  of  the  acromion  are  supposed  to  have 
been  ununited  epiphyses.  Fracture  of  the  coracoid  process  is  produced  by  indirect 
violence  applied  to  the  arm,  thereby  forcing  the  scapula  upward  and  driving  the 
coracoid  process  against  the  clavicle. 

Fractures  of  the  humerus  comprise  about  eight  per  cent,  of  all  fractures. 


PLATE  LXX. 


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1 


272 


FRACTURES   OF   THE    I '/'/'Hi;    I^TIiKMITY.  273 

They  nisiy  occur  through  any  of  tlic  various  divisions  of  the  bone,  as  the  ana- 
tomic neck,  the  tuberosities,  the  surgical  neck,  the  middle  third  of  the  shaft,  the 
external  or  internal  condylc,  the  shaft  immediately  almve  the  condyles  and 
between  the  condyles.  Separation  of  the  epiphysis  may  occur  at  either  extremity 

of   tile  bone. 

In  fracture  of  the  <iii<it»/ni<-  n<;-k  there  is  often  little,  if  any,  deformity  and 
displacement,  owing  to  the  fact  that  the  break  is  largely  within  the  capsule  of  the 
joint.  As  such  fractures  are  usually  due  to  indirect  violence,  the  head  of  the  bone 
may  be  forced  into  the  cancellous  tissue  of  the  lower  fragment  and  an  impacted 
fracture  result. 

In  fracture  through  the  r/rcntr,-  tiilx-i-oxitij  the  antero-posterior  diameter  of  the 
shoulder-joint  is  increased,  and  a  sulcus  exists  between  the  front  of  the  joint  and 
the  fragment.  The  rotundity  of  the  shoulder  is  altered  but  not  lost.  The  frag- 
ment is  drawn  upward  and  backward  by  the  action  of  the  supra-spinatus,  infra- 
spinatus,  and  teres  minor  muscles,  which  are  inserted  into  the  greater  tuberosity. 

In  fracture  of  the  surgical  neck  the  line  of  the  break  is  below  the  tuberosities, 
and  above  the  insertion  of  the  teres  major  and  latissimus  dorsi.  The  upper  frag- 
ment is  rotated  outward  and  slightly  abducted  by  the  action  of  the  muscles 
attached  to  the  greater  tuberosity.  The  lower  fragment  is  drawn  upward  toward 
the  axilla  by  the  biceps,  triceps,  coraco-brachialis.  and  deltoid  ;  and  inward  by  the 
pectoralis  major,  teres  major,  and  latissimus  dorsi  muscles.  Marked  displacement 
of  the  lower  fragment  is  prevented  by  the  long  head  of  the  biceps  in  front  and  the 
long  head  of  the  triceps  behind. 

In  persons  under  'twenty  years  of  age  epiphyseal  fmcfitre  is  more  likely  to 
occur  than  fracture  of  the  surgical  neck  of  the  humerus,  and  as  the  length  of  the 
bone  is  chiefly  derived  through  growth  of  this  upper  epiphyseal  cartilage,  consider- 
able shortening  is  likely  to  occur. 

In  fractures  of  the  shaft  of  the  humerus  the  displacement  will  depend  upon  the 
location  of  the  fracture.  If  it  be  above  the  insertion  of  the  deltoid  and  below 
the  insertion  of  the  pectoralis  major,  the  upper  fragment  will  be  drawn  inward  by 
this  latter  muscle  as  well  as  by  the  teres  major  and  latissimus  dorsi.  The  lower 
fragment  will  be  drawn  directly  upward  and  external  to  the  upper  fragment  by  the 
action  of  the  deltoid,  and,  indirectly,  by  the  biceps  and  triceps  and  the  coraco- 
brachialis  muscles.  If  the  fracture  be  immediately  below  the  insertion  of  the 
deltoid,  the  position  of  the  upper  fragment  is  little  altered  by  muscular  action, 
as  the  deltoid  is  antagonized  by  the  pectoralis  major,  latissimus  dorsi,  teres  major, 
and  coraco-brachialis.  On  account  of  the  usual  downward  and  outward  direction 
of  the  line  of  fracture,  the  lower  fragment  is  found  on  the  inner  side  of  the  upper, 
as  it  is  drawn  upward  by  the  biceps  and  triceps  muscles. 

18 


274  SURGICAL    .\\.\TOMY. 

When  the  lower  part  of  the  shaft  of  the  Immenis  is  hroken,  then-  is  hut  little 
displacement,  because  of  the  broad  attnelirnent  of  the  hrachialis  antic'us  in  front 
and  the  counterbalancing  influence  of  the  iriceps  behind. 

In  Kiifii-<i-ci>ii<li//ni<l  tVacture  the  displacement  is  similar  to  that  of  a  backward 
dislocation  of  both  bones  of  the  forearm.  The  upper  fragment  overrides  the  lower, 
and  the  latter  is  displaced  backward  by  the  action  of  the  brachialis  anticus  and 
bice] is,  and  upward  by  the  biceps  and  the  triceps.  The  brachialis  anticus  and 
biceps,  by  flexing  the  elbow-joint,  tilt  the  lower  fragment  backward. 

Fractures  of  the  i-nin/i/ha  are  not  very  frequent.  They  may  or  may  not  be 
associated  with  an  inlercondyloid  fracture.  The  main  deformity  is  a  widening  of 
the  elbow-joint,  with  downward  displacement  of  the  condyle. 

In  intercom! nli>i> I  fracture  the  deformity  is  widening  of  the  joint  and  inward 
displacement  of  the  olecranon. 

After  fracture  of  the  condyles  there  is  not  infrequently  seen  an  inward  deflec- 
tion of  the  bones  of  the  forearm  at  the  elbow.  In  the  normal  condition,  with  the 
forearm  extended  and  supinated,  the  radius  and  ulna  form  an  obtuse  angle  with 
the  humerus,  so  that  when  the  arm  lies  at  the  side  of  the  body,  the  hand  projects 
away  from  the  median  line  of  the  body.  By  an  upward  displacement  of  the 
inner  condyle,  or  a  downward  of  the  outer,  this  angle  may  be  lost,  and  the  so- 
called  "gun-stock  deformity,"  described  by  Allis,  is  then  produced. 

In  fractures  of  the  upper  end  of  the  humerus — i.  e.,  of  the  surgical  or  ana- 
tomic neck — the  circumflex  nerve  may  be  injured,  in  fracture  of  the  shaft  the 
musculo-spiral  nerve,  and  in  fracture  of  the  internal  condyle  the  ulnar  nerve. 
When  the  symptoms  of  nerve  injury  appear  shortly  after  or  at  the  time  of  the 
occurrence  of  the  fracture,  they  are  caused  by  laceration  or  pressure  by  a  frag- 
ment ;  but  if  they  develop  late,  they  are  the  result  of  pressure  by  callus.  The 
character  of  the  symptoms  presented  depends  upon  the  amount  of  pressure  exerted. 
Moderate  pressure  irritates  the  nerve,  and  causes  tingling  and  pain  in  the  area  of 
distribution  of  its  sensory  branches,  and  spasm  of  the  muscles  supplied  by  its  motor 
branches.  Greater  pressure  causes  anesthesia  and  trophic  disturbance  in  the  area 
supplied  by  its  sensory  fibers,  and  paralysis  and  atrophy  of  the  muscles  supplied 
by  its  motor  branches.  In  fracture  the  circumflex  nerve  is  rarely  injured  ;  injury 
to  the  musculo-spiral  and  ulnar  nerves  occasionally  occurs.  AVhen  the  circumflex 
nerve  is  involved,  there  is  pain  or  partial  or  complete  anesthesia  over  the  deltoid 
and  upper  part  of  the  triceps,  and  spasm  or  paralysis  of  the  deltoid  and  teres 
minor.  If  the  musculo-spiral  nerve  be  affected,  there  is  pain  or  more  or  less 
anesthesia  in  the  back  and  outer  part  of  the  arm  and  forearm,  and  spasm  or 
paralysis  of  the  muscles  which  the  nerve  supplies.  These  muscles  are  the  trice] is, 
anconeus,  supinator  longus,  extensor  carpi  radialis  longior,  extensor  carpi  radial  is 


PLATE  LXXI. 


276 


FRArrri!l-:s    OF    THE    T/'/V-.V,'    KXTHKM1TY.  Ill 

brcvior,  extensor  eonimuiiis  digitorum,  extensor  minimi  digiti,  extensor  carpi 
uliiiiris.  siqiinator  brevis,  extensor  ossis  metacarpi  pollicis.  extensor  longtis  pollicis. 
extensor  lirevis  pollicis,  and  extensor  indieis.  Paralysis  of  the  triee|is  is  unlikely 
because  of  the  high  origin  of  the  branches  to  that  muscle.  The  condition  which 
results  from  paralysis  of  the  musculo-spiral  nerve  is  known  as  "wrist-drop."  The 
hand  is  pronated  and  the  wrist  and  fingers  Hexed.  Loss  of  opposition  from  the 
extensors,  which  steady  the  fingers  during  flexion,  causes  loss  of  power  in  grasping 
objects. 

When  the  ulnar  nerve  is  affected,  there  is  pain  or  anesthesia  in  the  ulnar  side 
of  the  forearm  and  hand,  in  the  little  finger  and  ulnar  half  of  the  ring  finger,  and 
there  is  spasm  or  paralysis  of  the  flexor  carpi  ulnaris,  ulnar  side  of  the  flexor 
prothndus  digitorum,  the  palmaris  brevis,  short  muscles  of  the  little  finger,  two 
ulnar  lumbrieales,  inlerossei,  adductor  pollieis,  and  inner  head  of  the  flexor  brevis 
pollicis.  Paralysis  of  the  interossei  unbalances  t lie  state  of  equilibrium  existing 
between  the  flexors  and  extensors,  and  as  a  result  the  first  phalanges  are  extended 
and  the  distal  phalanges  partially  flexed.  This  produces  a  "  clnwcd  hand,"  or 
••  main  en  griffe."  Power  of  flexion  of  the  little  and  ring  fingers  is  lost,  and 
power  of  movement  of  the  thumb  is  much  diminished. 

Fracture  of  the  radius. — The  radius  usually  sustains  fracture  about  the 
lower  one-third,  where  it  occurs  much  more  frequently  than  in  the  middle  or 
upper  one-third. 

In  fracture  of  the  head  or  neck  of  the  radius  the  lower  fragment  is  carried 
upward  and  forward  by  the  biceps,  which  is  inserted  into  the  tuberosity.  Many 
surgeons  and  anatomists  claim  that  it  is  impossible  to  have  a  fracture  of  the  neck 
of  the  radius,  unless  it  be  complicated  by  some  other  fracture  or  a  dislocation. 
The  author  has  proved  by  X-ray  photography  and  subsequent  operation  that 
simple  fracture  of  the  neck  of  the  radius  does  occur. 

Fracture  of  the  radius  may  occur  between  the  insertion  of  the  biceps  and  that 
of  the  pronator  radii  teres,  although  such  a  fracture  is  very  rare.  The  upper  frag- 
ment would  be  strongly  supinated  by  the  action  of  the  biceps  and  the  supinator 
brevis,  and  the  lower  would  be  pronated  and  approximated  toward  the  ulna  by  the 
pronator  radii  teres  and  the  pronator  quadratus.  As  the  two  strong  supinators, 
the  biceps  and  supinator  brevis,  would  have  no  influence  over  the  lower  fragment, 
the  supinator  loiigus  could  not  counterbalance  the  action  of  the  pronator  radii 
teres  and  pronator  quadratus. 

Fracture  of  the  lower  end  of  the  radius  (Colics'  fracture)  is  the  most  frequent 
of  this  bone.  The  deformity  is  chiefly  caused  by  the  breaking  force,  which  pushes 
the  lower  fragment  backward  and  upward,  making  it  override  the  upper  fragment, 
which  is  forced  downward  and  forward.  The  alteration  of  contour  thus  effected  is 


278  SI'KGICAL  ANATOMY. 

known  as  the  "  silver-fork  deformity."  The  displacement  of  the  fragments  is 
partly  due  to  the  extensors  of  the  wrist  and  fingers.  The  hand  is  carried  to  the 
radial  side  by  the  supinator  longus,  the  extensores  carpi  radialis  longior  and 
liivvior,  and  the  extensors  of  the  thumb,  they  being  rendered  tense  by  the  displace- 
ment of  the  lower  fragment. 

The  ulna  may  be  fractured  at  any  point.  As  a  rule,  fracture  of  the  ulna  is 
caused  by  direct  violence,  and  for  this  reason  there  is  no  uniform  displacement  of 
the  fragments,  as  this  must  vary  with  the  angle  of  impact  at  which  the  breaking 
force  operates.  If  there  be  any  usual  direction  for  displacement  of  the  fragments, 
it  is  probable  that  the  lower  fragment  would  be  drawn  toward  the  radius  by  the 
action  of  the  pronator  quadratus.  The  upper  fragment  can  only  be  displaced  to 
any  extent  backward  or  forward,  because  of  its  connection  with  the  humerus  at 
the  elbow-joint. 

Fracture  of  the  coronoid  process  is  exceedingly  rare.  If  it  should  occur,  the 
process  will  probably  be  drawn  upward  by  the  brachialis  anticus,  which  is 
attached  to  its  base.  As  the  coronoid  process  forms  the  anterior  wall  of  the  greater 
sigmoid  cavity  of  the  ulna,  this  fracture  is  usually  associated  with  a  backward 
dislocation  of  either  this  bone  alone  or  of  both  the  radius  and  ulna. 

In  fracture  of  the  olecranon  process  the  displacement  of  the  upper  fragment  is 
always  upward,  and  is  determined  by  the  action  of  the  triceps.  The  extent  of  the 
displacement  depends  upon  the  degree  of  the  breaking  force  and  upon  the  extent 
of  the  rupture  of  the  ligaments  which  surround  the  elbow-joint.  If  the  forearm 
lie  markedly  flexed  at  the  time  the  fracture  occurs,  it  is  probable  that  the 
ulna  will  be  dislocated  forward  by  the  action  of  the  biceps  and  the  brachialis 
anticus. 

Fracture  of  both  bones  of  the  forearm  most  commonly  occurs  below  the 
middle,  where  they  are  least  protected  by  muscles.  When  the  fracture  is  com- 
plete, the  deformity  is  usually  very  slight.  In  incomplete,  or  "  green-stick," 
fracture  the  deformity  depends  upon  the  amount  of  bending  of  the  bones.  Occa- 
sionally there  is  sufficient  displacement  to  produce  an  angular  deformity. 

Simple  fractures  of  the  carpus  are  rare.  When  they  occur,  there  is  but 
little,  if  any,  displacement  of  the  fragments,  owing  to  the  firm  ligamentous  con- 
nections existing  between  the  bones. 

In  fractures  of  the  metacarpal  bones  there  is  but  little  displacement,  on 
account  of  the  attachments  of  the  ligaments,  and  the  position  of  the  flexor  and 
extensor  tendons  and  interossei  muscles ;  all  of  which  tend  to  hold  the  frag- 
ments in  place.  If  there  be  any  displacement,  the  proximal  end  of  the  distal 
fragment  will  project  on  the  back  of  the  hand,  resulting  in  shortening  produced 
by  the  fracturing  force  and  by  the  action  of  the  flexors  and  extensors.  , 


AMITTATIOXS.  :27',) 

The  displacement  in  fractures  of  the  phalanges  is  never  very  great.     AY  hen. 

present  it  is  usually  transverse  ami   duo  to  the  direction  of  the  breaking  force.      If 
the  line  of  fracture  he  oblique,  there  may  be  some  overlapping. 


AMPUTATIONS. 

In  amputations  the  following  considerations  should  be  borne  in  mind : 
(1)  Save  the  patient's  life.  (2)  Obtain  a  useful  stump.  (.">)  Secure  a  suilicieiit 
and  healthy  cutaneous  covering  for  the  end  of  the  stump,  with  little  redundant 
muscular  tissue  therein.  All  tendons  are  cut  even  with  the  end  of  the  bone 
or  bones  and  not  drawn  out,  as  it  is  desirable  that  they  adhere  to  the  cica- 
tricial  tissue  and  add  to  the  mobility  of  the  stump.  Large  nerves  should  be 
gently  drawn  out  and  severed  on  a  level  with  the  end  of  the  bone,  so  that  they 
will  retract  within  their  sheaths  and  the  bulbs,  or  false  neuromata,  which  form 
upon  their  cut  ends  will  not  be  included  in  the  cicatrix  and  cause  a  painful  stump. 

(4)  The  flaps  should  usually  be  made  by  dissection,  and  be  of  sufficient  length  to 
avoid  the   formation  of  a  conic  stump   and  allow  free   mobility  of   the    stump. 

(5)  The  resulting  scar  should  not  be  in  the  middle  of    the  end    of  the  stump, 
because  pressure  upon  the  scar  causes  pain,  and  usefulness  of  the  member  will   be 
thereby  lessened.      In  the   thigh  and   leg  it  should  be  situated  posteriorly  ;    this 
result  is  secured  by  making  a  long  anterior  and   a  short   posterior  flap.     In  this 
location  the  greater  contraction  of  the  muscles  divided  upon  the  dorsal  aspect 
tends  to  retract  the  scar  still  further  posteriorly.     At  the  wrist  or  ankle  or  in  the 
foot  a  palmar  or  plantar  flap  is  desirable,  as  it  is  best  adapted   fur  bearing  pressure. 

(6)  It  is  well  to  save  as  much  of  the  limb  as  can  be  retained  with  safety  and 
future    utility,    as   the    danger   of  the   operation    increases    with    the    length    of 
the  limb  removed.     (7)  A  deformed  and  ugly  living  appendage  is  likely  to  be  of 
greater  utility  than  the  best  artificial  one.     After  the  operation  is  completed,  the 
vessels  are  ligatured,  the  wound  is  cleansed,  drainage  is  established,  and  the  flaps 
are  held  in  apposition  by  sutures. 

In  amputation  of  the  phalanges  :  (1)  Save  as  much  as  possible,  especially  of 
the  thumb,  in  order  that  it  may  be  apposed  to  the  remaining  digits.  (2)  Do  not 
interfere  with  the  palm,  large  scars  of  which  may  be  painful  and  develop  epitheli- 
oma.  (3)  Do  not  remove  the  heads  of  the  metacarpal  bones  or  divide  the  trans- 
verse metacarpal  ligament,  as  the  hand  would  thus  be  weakened.  (4)  The  full 
breadth  of  the  hand  should  be  preserved. 

Amputations  are  performed  at  one  of  two  points — through  the  continuity  of 
the  bones  of  the  limbs  or  between  their  contiguous  extremities. 


SURGICAL   ANATOMY. 

<  >f  tin1  various  methods  of  amputation  which  have  lieen  adopted,  only  those 
wliich  have  proven  most  satisfactory  to  the  autlior  will  he  described. 

The  methods  of  amputation  adopted  hy  the  autlior  include  the-  following: 
The  circular,  the  modified  circular,  the  flap,  Teale's.  Speiice's,  Lister's,  and 
the  oval. 

The  method  adapted  to  any  operation  depends  upon  the  position,  conforma- 
tion, and  anatomy  of  the  part  to  he  amputated  and  upon  the  condition  of  the 
tissues  in  that  locality.  No  one  method  is  expedient  in  all  locations;  for  while  in 
one  place  the  circular  method  gives  good  results,  better  results  are  obtained  in  other 
situations  by  one  of  the  Hap  methods. 

The  circular  method. — In  the  original  circular  method  the  hone  and  all  other 
tissues  were  divided  at  the  same  level.  At  present  in  this  method  three  incisions 
are  made.  The  first  incision  divides  skin  and  superficial  fascia  and  separates  the 
superficial  from  the  deep  fascijc  ;  in  this  manner  a  cuff  of  skin  and  superficial 
fascia  equal  in  length  to  one-half  of  the  diameter  of  the  limb  is  dissected  up  and 
everted  and  rolled  up  as  high  as  possible.  The  second  incision  divides  the  deep 
fascia  and  underlying  tissues  at  the  level  of  the  attachment  of  the  cuff  of  skin 
and  superficial  fascia  ;  and  the  third  divides  the  bone  as  high  as  possible  while  the 
soft  tissues  are  retracted.  The  resulting  wound  is  in  the  form  of  a  pit  with  the 
sawed  end  of  bone  at  the  bottom;  in  this  way  the  danger  of  a  resulting  conic 
stump  is  eliminated.  The  advantages  of  the  circular  method  are  that  in  a  fleshy 
limb  it  avoids  a  redundance  of  useless  muscular  tissue  in  the  stump.  All  the 
vessels  are  divided  transversely,  contract  and  retract  well,  while  unnecessary  hemor- 
rhage is  avoided.  The  surface  of  the  wound  is  smaller  than  in  other  methods; 
for  this  reason  union  occurs  more  promptly  and  the  resulting  cicatrix  is  smaller. 
The  disadvantages  are  that  the  cicatrix  extends  across  the  middle  of  the  end  of 
tlie  stump  and  is  adherent  to  the  bone.  This  is  likely  to  cause  a  tender  stum}),  and 
in  the  lower  extremity  will  be  a  great  disadvantage,  as  the  patient  can  not  bear 
any  weight  upon  the  stump.  As  the  corners  of  the  stump  wound  are  always 
puckered,  the  edges  of  skin  do  not  lie  in  apposition  and  union  does  not,  therefore, 
occur  quickly. 

The  modified  circular  method. — Tn  this  method  two  semilunar  incisions  are 
made  through  skin  and  superficial  fascia,  dissecting  up  two  short  flaps  equal  in 
length  to  one-quarter  of  the  diameter  of  the  limb.  These  flaps  are  then  everted 
and  a  short  cuff  of  skin  and  superficial  fascia  rolled  up  as  in  the  circular  method. 
Then  the  muscles  and  deep  fascia  are  divided  at  the  level  of  the  retracted  skin  on 
the  anterior  surface  of  the  limb,  and  on  the  posterior  surface  of  the  limb  at  a 
distance  from  the  retracted  skin  equal  to  one-fourth  of  the  diameter  of  the  limb. 
The  soft  parts  are  retracted  from  the  bone,  which  is  sawed  at  the  highest  possible 


Icvd.  This  method  differs  1'rom  the  circular  method  only  in  having  two  small 
Haps  of  skin  and  superficial  fascia  and  a  short  sleeve  of  skin  and  superficial  fascia 
instead  of  a  long  sleeve  of  skin  and  superficial  fascia  to  cover  the  stum]).  The 
circular  method  is  well  adapted  to  amputations  of  the  arm,  where  the  part  does 
not  taper  from  above  downward.  Where  the  part  tapers,  as  in  a  muscular  fore- 
arm or  calf  of  the  leg,  the  modified  circular  is  best.  Both  the  circular  and 
modified  circular  methods  are  well  adapted  to  amputation  of  the  arm  and  fore- 
arm where  a  seal1  across  the  middle  of  the  end  of  the  stump  is  not  of  serious  dis- 
advantage. These  two  methods  give  the  longot  possible  stump. 

The  flap  method. — The  flaps,  are  made  by  cutting  from  without  inward  (dis- 
sect ion),  or  from  within  outward  (transfixion).  The  flap  furthest  from  the  main 
vessel  is  usually  made  first.  The  advantages  of  this  method  are  the  following: 
It  is  more  easily  and  readily  performed  than  the  circular  method  ;  it  gives  a 
thicker  cushion  for  the  stump,  as  the  muscular  tissue  of  the  flaps  disappears  while 
some  fibrous  tissue  of  the  muscles  remains.  The  disadvantages  are  the  following: 
Many  of  the  blood-vessels  of  the  part  are  divided  obliquely  and  do  not  contract 
and  retract  well,  and  in  ligaturing  them  it  is  necessary  to  exercise  more  care  in 
order  that  the  vessels  maybe  tied  entirely  above  where  they  have  been  severed  ; 
on  account  of  the  irregular  contraction  of  the  various  muscles  divided,  the  stump 
may  be  irregular  ;  the  surface  of  the  wound  is  larger  than  in  the  circular  method, 
and  very  thick  muscular  flaps  are  in  themselves  a  disadvantage.  The  transfixion 
method  of  making  flaps  is  more  rapid  than  the  method  by  dissection,  but  the  skin 
is  divided  in  an  uneven  line  and  the  flaps  are  likely  to  be  too  thick. 

The  first  objection  can  be  avoided  by  dividing  the  skin  and  superficial  fascia 
by  dissection  and  then  dividing  the  muscles,  deep  fascia,  vessels,  and  nerves  by 
transfixion. 

The  dissection  method  of  making  flaps  requires  more  time,  but  the  skin  is 
divided  in  the  manner  desired  and  the  flaps  may  be  made  of  proper  thickness. 
When  there  are  ulcers,  sinuses,  or  malignant  growths  the  flap  may  be  shaped  as 
circumstances  demand. 

Teale's  method  consists  of  the  formation  of  a  long  and  a  short  rectangular 
flap.  The  breadth  of  each  flap  is  equal  to  one-half  of  the  circumference  of  the 
limb.  The  length  of  the  anterior  flap  is  equal  to  one-half  of  the  circumference  of 
the  iimb,  and  that  of  the  short  flap  to  one-fourth  of  the  length  of  the  long  flap. 
As  the  long  flap  covers  the  end  of  the  bone  it  should  not  contain  the  large  vessels, 
and  for  this  reason  it  is  taken  from  the  front  of  the  leg  in  amputations  through  the 
tibia  and  fibula,  in  the  forearm  from  the  dorsal  surface,  and  just  above  the  knee 
the  long  flap  should  be  taken  from  the  antero-external  surface.  This  method  is 
used  above  the  ankle,  immediately  above  the  knee,  and  sometimes  in  the  forearm. 


282  SUlKiK'M.    ANATOMY. 

The  advantages  of  this  method  are  the  following :  The  bone  is  well  covered,  the 
wound  is  in  a  position  to  allow  free  drainage,  the  cicatrix  is  not  upon  the  end  of 
the  stump  and  hence  is  not  likely  to  cause  pain  from  pivssmv  produced  by  an 
artificial  limb.  The  chief  disadvantages  are  as  follows:  The  great  length  of  one 
of  the  Haps  necessitates  a  very  high  amputation;  the  operation  requires  much 
time,  as  the  flaps  must  be  accurately  outlined;  the  doubling  of  the  long  flap  by 
pressure  upon  the  vessels  may  impair  its  nutrition;  in  malignant  disease  recur- 
rence often  takes  place  in  one  of  the  flaps  on  account  of  its  length,  which  makes  it 
more  difficult  to  avoid  including  involved  tissue;  in  injury  of  the  soft  parts  an 
unnecessarily  high  amputation  is  required  to  secure  good  flaps;  if  the  flaps  fail  to 
unite  by  first  intention,  the  sagging  of  the  long  flap  prolongs  recovery  by  increas- 
ing the  space  to  be  filled  by  granulation  tissue  ;  the  area  of  the  wound  is  extensive, 
and  too  much  bone  is  sacrificed. 

In  Spence's  method  a  long  anterior  and  a  short  posterior  flap  are  made.  The 
long  flap  is  not  so  long,  and  the  short  flap  is  longer  than  in  Teale's  method,  and 
the  tissues  are  cut  obliquely  from  without  inward  to  the  bone.  The  soft  parts  are 
retracted  from  the  bone,  which  is  sawed  two  inches  above  the  bases  of  the  flaps. 
This  method  is  best  adapted  to  the  lower  third  of  the  thigh  and  to  a  very  muscular 
limb.  The  advantages  are  :  That  the  long  flap  is  not  doubled  upon  itself;  that  if 
union  by  first  intention  does  not  occur,  there  is  not  much  tendency  to  separation 
of  the  flaps  and  the  wound  is  more  manageable ;  that  a  good  covering  is  afforded 
for  the  stump,  and  that  the  cicatrix  is  not  upon  the  center  of  the  end  of  the  stump. 

In  Lister's  method  a  long  anterior  flap,  equal  in  length  to  two-thirds  of  the 
diameter  of  the  limb,  and  a  short  posterior  flap,  equal  in  length  to  one-half  of  that 
of  the  anterior  flap,  are  made.  The  flaps  are  procured  by  dissection,  and  are 
chiefly  composed  of  skin  and  superficial  fascia — although  some  deep  fascia  and 
muscular  tissue  may  be  included  in  the  base  of  the  anterior  flap  so  that  its  blood 
supply  may  be  as  plentiful  as  possible.  The  flaps  are  raised  and  the  remainder  of 
the  soft  tissues  divided  at  the  level  of  the  bases  of  the  flaps.  The  soft  tissues  are 
forcibly  retracted  for  a  distance  equal  to  one-fourth  of  the  diameter  of  the  limb, 
and  the  bone  divided  as  high  as  possible.  If  retraction  of  the  soft  parts  be  impos- 
sible, it  will  be  necessary  to  carry  a  lateral  incision  upward  from  the  points  of 
junction  of  the  two  flaps,  so  that  the  bone  may  be  divided  at  a  sufficiently  high 
level.  In  the  thigh  it  is  necessary  to  retract  the  soft  parts  a  distance  equal  to 
one-half  the  diameter  of  the  limb  before  sawing  the  bone.  In  the  lower  part  of 
the  forearm  and  leg  the  anterior  flap  must  be  equal  in  length  to  the  diameter  of 
the  limb,  and  the  posterior  flap  in  length  equal  to  one-half  the  diameter  of  the 
limb.  Such  modifications  are  required  in  these  locations  because  the  bones  occupy 
a  large  part  of  the  diameter  of  the  limb. 


AMPUTATIONS   OF  THE   UPPER  EXTREMITY.  283 

The  oval  method  is  similar  to  the  circular,  except  that  it  has  a  longitudinal 
incision  at  one  side.  When  this  cut  is  very  long,  the  incision  is  said  to  be  racket- 
shaped.  This  method  is  best  adapted  to  amputation  of  the  fingers  and  toes. 

Amputation  of  the  phalanges. — Phalanges  are  usually  amputated  because  of 
injury,  or  the  results  of  whitlow  or  felon.  The  base  of  the  phalanx  may  not  be 
affected  by  necrosis,  as  the  periosteum  is  protected  by  the  insertions  of  the  flexor 
and  extensor  tendons.  In  removing  a  portion  of  the  finger  through  the  continuity 
of  the  phalanx,  two  oval  flaps — one  anterior  and  one  posterior — are  made.  The 
palmar  flap  is  the  longer,  in  order  to  preserve  as  much  as  possible  acute  tactile 
sense  for  the  end  of  the  stump.  The  structures  divided  will  depend  upon  the 
distance  of  the  incision  from  the  metacarpal  bone  and  the  finger  amputated. 
In  these  amputations  the  skin  and  superficial  fascia,  with  the  collateral  digital 
arteries,  which  receive  blood  from  both  the  radial  and  ulnar  arteries,  will  be 
divided.  The  nerves  severed  in  the  amputations  are,  in  the  case  of  the  little  finger, 
branches  of  the  ulnar  nerve  ;  of  the  ring  finger,  branches  of  the  ulnar,  median, 
and  radial  nerves  ;  of  the  middle  and  index  fingers  and  thumb,  branches  of  the 
median  and  radial  nerves. 

In  amputation  through  the  last  phalanx  no  tendons  will  be  divided.  In 
amputations  of  the  distal  phalanges  of  the  fingers,  the  tendons  of  the  extensor 
communis  digitorum  and  flexor  profundus  digitorum  are  divided.  When  ampu- 
tating the  second  phalanx  of  the  fingers,  the  tendons  of  the  flexor  sublimis  and 
flexor  profundus  digitorum  and  extensor  communis  digitorum  are  severed.  In 
amputations  of  the  first  phalanx  of  the  thumb,  the  tendons  of  the  extensor  primi 
internodii  pollicis,  extensor  secundi  internodii  pollicis,  flexor  longus  pollicis,  and 
of  the  short  muscles  of  the  thumb  are  divided.  In  amputating  the  second 
phalanx  of  the  thumb,  the  tendons  of  the  flexor  longus  pollicis  and  extensor 
secundi  internodii  pollicis  are  severed ;  in  amputating  the  proximal  phalanx 
of  the  fingers,  the  tendons  of  the  superficial  arid  deep  flexors,  the  common 
extensor,  the  interosseous  and  lumbrical  tendons  are  divided. 

The  line  of  the  interphalangeal  joints  is  opposite  the  transverse  furrows  on 
the  palmar  surface  of  the  fingers,  and  immediately  to  the  proximal  side  of  the 
ridge  on  the  base  of  the  respective  phalanges. 

In  disarticulating  the  metacarpo-phalangeal  joints  the  preferable  incision  is 
one  commencing  over  the  distal  end  of  the  dorsal  surface  of  the  metacarpal  bone, 
carried  around  both  sides  of  the  finger  and  through  the  crease  of  the  palmar 
surface  of  the  proximal  phalanx.  The  structures  divided  are  the  tendons  of  the 
common  extensor,  flexor  sublimis  digitorum,  flexor  profundus  digitorum.  iriter- 
osseous  and  lumbrical  tendons,  the  lateral  and  anterior  metacarpo-phalangeal 
ligaments,  and  the  collateral  digital  vessels  and  nerves. 


iis4  SURGICAL    .I.V.I  TOMY. 

Disarticulation  of  the  four  metacarpal  bones  of  the  fingers. — In  disarticu- 
lating these  Indies  from  the  cari>ns  by  transfixion  tlit.1  point  of  tin-  knife  is  inserted 
at  the  junction  of  the  tnetacarpal  lione  of  the  little  tinker  \vitli  tin-  earpus,  pushed 
through  the  soft  parts  of  the  palm  of  the  hand  close  to  the  hones,  and  brought 
out  in  the  fleshy  tissue  between  tin- thumb  and  index  finger.  The  knife  is  then 
carried  downward  and  forward  (away  from  the  bones),  cutting  through  the  flexor 
brevis  minimi  digiti,  opponens  minimi  digit i,  abductor  minimi  digiti,  adductor 
pollicis,  palmaris  brevis  and  lumbricales  muscles,  the  tendons  of  the  flexor  sub- 
limis  digitorum  and  flexor  profundus  digitorum,  tin-  profunda  branch  of  the  ulnar 
artery  and  nerve,  the  deep  palmar  arch,  the  digital  arteries  and  nerves,  the  deep 
and  superficial  palmar  fascia',  and  the  skin.  The  hand  is  then  pronated,  and  a 
semicircular  incision,  with  the  convexity  downward,  carried  across  the  dorsal 
surface  joining  the  two  ends  of  the  palmar  incision.  The  dorsal  incision  divides 
the  skin  and  superficial  fascia,  some  of  the  radicles  of  the  radial,  anterior  and 
posterior  ulnar  veins,  branches  of  the  radial  and  ulnar  nerves,  the  deep  fascia,  the 
tendons  of  the  extensor  carpi  nlnaris,  extensor  minimi  digiti,  extensor  communis 
digitorum,  extensor  indicis.  the  synovial  sheaths  of  the  tendons,  the  dorsal  inter- 
osseous  arteries,  and  the  dorsalis  indicis.  These  two  flaps  are  then  dissected 
upward  until  the  articulation  is  reached.  The  metacarpal  bones  should  be  disar- 
ticulated, beginning  on  the  palmar  surface.  The  capsular,  palmar,  dorsal,  and 
interosseous  ligaments  are  severed  and  the  hand  removed.  The  sheaths  of  the 
flexor  and  extensor  tendons  should  be  sutured,  there  being  less  liability  of  infection 
traveling  along  them  than  if  they  were  allowed  to  remain  open. 

Amputation  of  the  thumb  at  the  carpo-metacarpal  articulation.  —  In 
amputating  the  thumb  at  the  carpo-metacarpal  articulation  the  incision  should  be 
made  along  the  junction  of  the  dorsal  and  palmar  integument  and  around  the  base 
of  the  proximal  phalanx.  The  proximal  extremity  of  the  incision  commences  over 
the  articulation  of  the  metacarpal  bone  with  the  carpus,  about  one  inch  from  the 
styloid  process  of  the  radius.  In  this  amputation  care  must  be  exercised  to  avoid 
injuring  the  radial  artery,  which  is  closely  related  to  the  base  of  the  metaearpal 
bone  of  the  thumb.  The  following  structures  are  divided  :  The  skin,  superficial 
and  deep  fascia1,  branches  of  the  radial  and  median  nerves,  the  dorsales  pollicis  and 
princeps  pollicis  arteries,  the  tendon  of  the  flexor  longus  pollicis,  the  short  muscles 
of  the  thumb,  the  abductor  indicis  (first  dorsal  interosseous),  and  the  capsular 
ligament.  A  lateral,  rather  than  a  dorsal,  incision  may  also  be  made  in  removing 
the  metacarpal  bone  of  the  little  finger. 

Disarticulation  of  the  radio-carpal  or  wrist-joint. — That  the  movements  of 
pronation  and  supination  of  the  stump  may  be  retained,  the  wrist,  rather  than 
a  higher  position  on  the  arm,  is  selected  for  the  amputation.  This  operation  is 


PLATE  LXXII. 


MedianN. 

Flexor  carpi  Radia/is  M. 
Flexor Lnnjjus  pal HcisM. 

Radial  A. 
RadialN. 


Palmar/s  /nngus  Tendon 
FlexorSublim/sdigirorum  M. 

UlnarA. 
\UlnarN. 

,  Flexor  prof undus  d /giro rum  M. 


Supinaf-arlongusTent/on 


/onginr  Tendon 

Extensor  carpi  rdd/a//s 
AreworAt. 


Anterior  inferosseous/V. 
Anterior  interosseousA. 

/nrerosseoi/BMembrj/ie 


Extensor  carpi ulnans  M. 
Extensor  languspo//ir./sM. 
Extensor  min/m/dij?/fiM. 
Posterior  interosseas  ft. 
Posterior  inferasseus  A . 
Extensor  055/5  mef-aarpi po///cis  M. 


TRANSVERSE  SECTION  OF  FOREARM  JUST  BELOW  MIDDLE. 
286 


AMPUTATIONS   OF  THE   UPPER  EXTREMITY.  287 

usually  |>(Tl'<>niir<l  after  injuries,  and  not  when  the  wrist  or  carpal  joints  are 
diseased,  because  then  the  inferior  radio-ulnar  joint  is  affected  and  these  move- 
ments would  necessarily  be  lost.  This  amputation  is  performed  by  making 
anterior  and  posterior  semilunar  flaps,  with  their  convexity  downward.  The 
anterior  incision  extends  from  one  styloid  process  to  the  other,  and  passes  through 
the  skin;  superficial  fascia  with  its  small  nerves,  arteries,  and  veins;  the  deep 
fascia  ;  and  the  following  structures  in  the  order  named  from  the  ulnar  to  the 
radial  side  :  The  tendon  of  the  flexor  carpi  ulnaris,  the  ulnar  nerve,  ulnar  artery 
and  its  vense  comites,  the  four  tendons  of  the  flexor  sublimis  digitorum,  the  four 
tendons  of  the  flexor  profundus  digitorum,  the  palmaris  longus,  the  median  nerve 
and  artery,  the  flexor  longus  pollicis,  the  tendon  of  the  flexor  carpi  radialis,  and 
the  snperficialis  vohe  artery. 

The  posterior  incision  divides  the  following  structures:  Rkin,  superiicial 
fascia,  branches  of  the  radial  and  ulnar  vessels  and  nerves,  the  radial,  anterior, 
and  posterior  ulnar  veins,  the  posterior  carpal  branch  of  the  ulnar  artery,  the 
tendons  of  the  extensor  carpi  ulnaris,  extensor  minimi  digiti,  extensor  communis 
digitorum,  extensor  indicis,  extensores  carpi  radialis  brevior  and  longior,  extensor 
secundi  internodii  pollicis,  extensor  primi  internodii  pollicis,  extensor  ossis  meta- 
carpi  pollicis,  the  radial  artery  and  its  vena;  comites,  the  anterior  interosseous 
artery,  the  posterior  interosseous  artery  and  nerve,  the  anterior,  posterior,  external 
lateral,  and  internal  lateral  ligaments. 

The  principal  arteries  1<>  lie  ligated  are  the  radial  and  ulnar.  The  radial 
will  be  found  on  the  radial  side  of  the  forearm,  on  the  external  lateral  ligament 
of  the  wrist-joint  just  below  the  styloid  process  of  the  radius.  The  ulnar  artery 
wrill  be  found  on  the  anterior  aspect  of  the  forearm,  just  internal  to  the  tendon 
of  the  flexor  carpi  ulnaris,  and  external  to  the  tendons  of  the  flexor  sublimis 
digitorum. 

Amputation  at  the  middle  of  the  forearm. — This  operation  is  generally  per- 
formed by  the  antero-posterior  flap  method.  The  anterior  incision  is  semilunar, 
with  its  convexity  downward,  passes  from  one  border  of  the  forearm  to  the  other, 
and  divides  skin,  superficial  fascia,  the  radial,  median,  and  anterior  ulnar  veins, 
the  anterior  branch  of  the  musculo-cutaneous  nerve,  the  anterior  branch  of  the 
internal  cutaneous  nerve,  cutaneous  branches  of  the  radial  and  ulnar  arteries,  the 
deep  fascia,  the  flexor  carpi  ulnaris,  the  ulnar  vessels  and  nerve,  the  flexor  sublimis 
digitorum,  the  palmaris  longus,  the  flexor  carpi  radialis,  the  median  nerv^3  and 
artery,  the  flexor  profundus  digitorum,  flexor  longus  pollicis,  the  radial  vessels  and 
nerve,  and  the  supmator  longus. 

The  posterior  incision  divides  the  skin,  the  superficial  fascia,  the  posterior 
ulnar  vein,  the  posterior  branch  of  the  internal  cutaneous  nerve,  the  inferior 


288  SURGICAL   AXAToMY. 

external  cutaneous  branch  of  the  musculo-spiral  nerve,  the  posterior  branch  of  the 
musculo-cutaneous  nerve,  cutaneous  branches  of  tlie  radial  and  ulimr  arteries,  the 
deep  fascia,  the  extensor  carpi  ulnaris.  extensor  mininii  digiti,  extensor  eoiuniunis 
digitorum.  extensores  carpi  radialis  longior  ami  bivvinr.  extensores  primi  and 
M'cimdi  internodii  pollieis,  extensor  ossis  rnetacarpi  pollieis,  and  the  posterior 
interosseous  vessels  ami  nerve.  The  interosseous  membrane  and  the  anterioi1 
interosseous  vessels  and  nerve  are  divided.  The1  bones  should  then  lie  sawed, 
and  the  main  vessels  Heated.  These  will  be  the  radial  artery,  which  will  be 
found  between  the  pronator  radii  teres  and  snpinator  longns  muscles;  the  ulnar 
artery,  between  the  flexor  carpi  ulnaris,  the  flexoivs  snblimis  and  profundus 
digitorum  ;  the  anterior  interosseous  artery,  on  the  anterior  surface  of  the  inter- 
osseous membrane;  and  the  posterior  interosseous  artery,  between  the  superficial 
and  deep  extensors. 

Amputation  of  the  elbow-joint. — The  most  satisfactory  method  for  per- 
forming this  operation  is  by  transfixion.  The  knife  should  be  introduced  about 
three-quarters  of  an  inch  below  the  internal  condyle  of  the  hurnerus,  with  the 
forearm  supinated  and  slightly  flexed.  The  object  in  flexing  the  forearm  is  to 
relax  the  anterior  ligament  so  that  it  can  be  transfixed  when  the  knife  passes 
over  the  joint.  The  point  of  the  knife  should  emerge  from  the  radial  side  of  the 
forearm  the  same  distance  below  the  external  condyle.  The  knife  should  then  be 
carried  down  the  forearm  for  about  four  inches  and  brought  abruptly  to  the 
surface.  The  structures  severed  will  be  the  anterior  ligament  of  the  joint,  the 
brachialis  anticus,  the  snpinator  brevis,  the  posterior  interosseous  nerve,  the 
tendon  of  tlie  biceps,  the  extensor  carpi  radialis  lougior,  the  supinator  longns, 
the  flexor  profundus  digitorum,  flexor  longus  pollieis,  the  common  interoaseous 
or  anterior  and  posterior  interosseous  vessels,  the  anterior  interosseous  nerve,  the 
median  artery  and  nerve,  the  radial  vessels  and  nerve,  the  ulnar  vessels  and  nerve, 
the  posterior  ulnar  recurrent  artery,  the  superficial  flexors,  the  deep  fascia,  the 
superficial  fascia,  the  radial,  anterior  and  posterior  ulnar  and  median  veins,  the 
anterior  and  posterior  branches  of  the  musculo-cutaneous  nerve,  the  anterior 
branch  of  the  internal  cutaneous  nerve,  and  skin.  A  posterior  incision  should 
then  be  made  directly  across  the  back  of  the  forearm,  over  the  base  of  the 
olecranon,  so  as  to  connect  the  two  ends  of  the  anterior  incision  when  a  flap  of 
skin  and  superficial  fascia  is  raised  as  high  as  the  tip  of  the  olecranon.  This 
incision  divides  the  skin,  superficial  fascia,  the  inferior  external  cutaneous  branch 
of  the  musculo-spiral  and  the  posterior  branch  of  the  internal  cutaneous  nerve. 
The  knife  should  then  be  passed  between  the  head  of  the  radius  and  the  humerus, 
and  then  across  the  front  of  the  joint  between  the  coronoid  process  of  the  ulna 
and  the  humerus,  severing  the  internal  and  external  lateral  ligaments  and  part 


1!) 


PLATE  LXXIII. 


Cepha/icV. 
Brae  hi a/i s  Anf/cusM. 


B/ceps  m.  Superficial  fascia 


Muscu/o  cutaneous /V. 


Deep  fascia 
Med/an/V. 


fx/ernal /nfermuscu/ar 
5ept-um. 

Outer  Head  of  Triceps  M. 


Muscu/vspfra/M 

Superior  ProfuntiA W$£^$^J8<1? 

\T    VvV-v"  «v'-  '-  -•"',"^W--C*  >*f~ 

\  ^g5^|g|l" 

\\.  \v-    •   .-..•«;'Sfc-v.  --- 
Long  Head  of  Triceps  M. 


Vena  comes 
Brachial  A. 
Internal  Cutaneous  N. 
Bas/t/cV. 
U/narH. 

/nferiarProfundaA. 


fafema/ /nfermuscu/ar  Septum. 


/finer  head  of  Tr/cepsM. 


TRANSVERSE  SECTION  OF  ARM  BELOW   INSERTION  OF  DELTOID   M. 

290 


PLATE  LXXIV, 


Muscula-cutaneaus  Af. 


Biceps  M. 

\l/e/?3  comes. 
\Brachidl 'A. 


Jupingf-arLnngusM. 

Radial  recurrent  A . 

Muscula-spiral  N. 


External Intermuscular 
Septum 

Posterior  ArticularBr. 
oFSuperiorProfundaA. 


MedianN. 
Vena  comes. 


Internal  [ufaneousN. 
Basilic  V. 


Internal  Intermuscu/ar 

Septum 
Inferior  ProtundaA. 

Ulnar  V. 


Triceps  M. 


TRANSVERSE  SECTION  OF  ARM  ABOVE  CONDYLES  OF  HUMERUS. 

291 


AMPUTATIONS   OF  THE   UPPER  EXTREMITY.  293 

of  the  posterior  ligament.  Next  siw  through  the  base  of  the  olecranon,  and 
remove  the  forearm  by  cutting  the  supinator  brevis,  interossoous  recurrent  artery, 
anconeus,  extensor  carpi  radialis  brevior,  extensor  communis  digitorum,  extensor 
carpi  ulnaris,  flexor  carpi  ulnaris,  and  deep  fascia. 

The  principal  vessels  to  be  ligaled  are  the  radial,  ulnar,  common  interossemi- 
or  anterior,  and  posterior  inlerosseous,  posterior  ulnar  recurrent,  and  the  inter- 
osseuus  recurrent  artery.  Tlie  radial  artery  will  be  found  on  the  radial  side 
of  the  Hap,  just  beneath  the  ulnar  margin  of  the  supinator  longus  muscle.  The 
ulnar  artery  will  be  found  between  the  flexor  sublimis  digitorum  and  the  flexor 
carpi  ulnaris.  The  common  interosseous  or  anterior  and  posterior  interosseous 
arteries  will  be  severed  near  their  origin. 

Amputation  through  the  middle  of  the  arm. — The  circular  or  the  antero- 
posterior  flap  method  may  be  used  in  this  amputation.  In  either  the  following 
structures  will  be  severed  on  the  front  and  inner  side  of  the  arm  :  Skin,  superficial 
fascia,  intercosto-humeral  nerve,  the  internal  cutaneous  and  external  cutaneous 
branches  of  the  musculo-spiral  nerve,  a  cutaneous  branch  of  the  circumflex 
nerve,  Ilie  lesser  internal  cutaneous  nerve  (nerve  of  Wrisberg),  internal  cuta- 
neous nerve,  branches  of  the  superior  and  inferior  profunda  arteries,  the  cephalic 
vein,  the  deep  fascia,  the  biceps  and  brachialis  anticus  muscles,  the  musculo- 
cutaneous  nerve,  the  median  nerve,  the  brachial  artery  and  its  vena?  comites, 
the  basilic  vein,  and  the  ulnar  nerve ;  on  the  posterior  aspect  of  the  arm, 
the  triceps  muscle,  the  musculo-spiral  nerve,  the  superior  profunda  artery, — the 
musculo-spiral  nerve  and  the  superior  profunda  artery  will  be  seen  immediately 
behind  the  bone,  in  close  relation  to  that  structure,  and  the  brachial  artery  beneath 
the  inner  border  of  the  biceps  muscle. 

Amputation  at  the  shoulder-joint. — This  amputation  is  performed  for  injury, 
tumors, — malignant  or  benign, — and  disease  of  the  joint.  But  one  of  the  numerous 
methods  of  amputation  at  the  shoulder-joint  is  described  below,  because  practically 
the  same  structures  are  divided  in  all  methods.  The  most  important  requisite  is 
the  surgeon's  knowledge  of  the  anatomy  of  the  parts  rather  than  of  the  different 
operations.  The  author  prefers  Spence's  operation, — a  modification  of  the  oval 
method.  It  is  especially  adapted  to  those  cases  of  injury  where  there  has  been 
much  comminution  of  the  humerus.  The  posterior  circumflex  artery  is  not 
severed,  the  head  of  the  bone  can  be  disarticulated  very  readily,  and  the  resulting 
stump  is  generally  full  and  round.  The  incision  extends  from  a  point  just 
external  to  the  coracoid  process,  downward,  in  a  line  with  the  humerus,  to  a  point 
just  below  the  attachment  of  the  pectoralis  major  muscle.  The  following  struc- 
tures are  divided  :  Skin,  .superficial  fascia,  supra-acromial  branches  of  the  cervical 
plexus  of  nerves,  branches  of  the  anterior  and  posterior  circumflex  vessels,  the. 


294  WRGICAL  ANATOMY. 

deep  fascia,  the  cephalic  vein,  the  humeral  branch  of  the  acromio-thoracic  artery, 
the  deltoid,  the  peetoralis  major,  and  the  anterior  circumflex  vessels.  The  incision 
is  then  carried  backward,  in  a  gentle  curve,  to  the  posterior  border  of  the  axilla. 
The  skin  and  superticial  fascia,  with  twigs  of  the  posterior  circumflex  artery  and 
circumflex  nerve,  the  cephalic  vein,  the  deep  fascia,  and  the  deltoid  muscle  will  be 
severed. 

The  posterior  flap  can  now  be  readily  stripped  from  the  bone  and  joint.  The 
flap  will  carry  with  it  the  terminal  part  of  the  circumflex  nerve  and  posterior  cir- 
cumflex vessels  which  enter  its  deep  surface.  The  muscles  attached  to  the  greater 
tuberosity  are  then  to  be  severed.  They  are  the  supra-spinatus,  infra-spinatns.  and 
teres  minor.  The  subscapularis  is  next  detached  from  the  lesser  tuberosity,  the 
long  head  of  the  biceps  divided,  and  the  joint  opened  by  dividing  the  capsular 
ligament.  The  arm  is  carried  well  inward,  thus  causing  the  head  of  the  humerus 
to  pass  from  the  glenoid  cavity.  Before  proceeding  further  a  slight  dissection 
of  the  axilla  may  be  made  to  expose  the  axillary  vessels,  when  they  may  be 
ligated  before  the  remaining  soft  parts  arc  severed  ;  or  the  knife  may  be  carried 
downward  close  to  the  bone  on  its  internal  aspect,  the  insertion  of  the  teres  major 
and  latissimus  dorsi  muscles  severed,  and  the  anterior  flap  made  by  cutting  from 
within  outward.  Care  must  be  taken  to  have  an  assistant  follow  the  knife  down- 
ward with  his  fingers  in  contact  with  the  vessels,  and  the  outward  cut  should  not 
be  made  until  the  surgeon  is  sure  that  the  vessels  are  controlled  by  the  assistant, 
The  last  incision  severs  the  triceps  muscle  ;  the  brachial  vessels  ;  basilic  vein  :  the 
anterior  circumflex  artery  ;  the  ulnar,  median,  musculo-spiral,  internal  cutaneous, 
lesser  internal  cutaneous,  internal  cutaneous  branch  of  the  musculo-spiral,  and  the 
intcrcosto-humeral  nerve;  the  deep  fascia;  superficial  fascia,  and  skin. 


LIGATIONS  OF  THE  ARTERIES. 

Arteries  are  ligatured  in  the  treatment  of  aneurysms ;  to  arrest  hemorrhage ; 
check  malignant  growths;  and  previous  to  some  operations,  as  amputation  at  the 
shoulder  and  removal  of  the  tongue. 

Aneurysms  are  treated  by  medical  and  surgical  means.  The  medical  treat- 
ment consists  of  rest  in  bed  in  the  recumbent  position.  Whenever  possible,  the 
part  affected  should  be  placed  in  such  a  position  as  to  impede  the  flow  of  the  blood 
current  through  the  aneurysm,  but  not  interfere  with  the  return  circulation.  The 
diet  should  be  non-stimulating,  easily  digested,  in  small  quantity,  and  contain 
little  liquid.  All  excitement  must  be  avoided.  Depletion  may  be  practised  to 


PLATE  LXXV, 


m. 


I.  ANEURYSMAL  VARIX.  II,  VARICOSE  ANEURYSM.  Ill,  METHOD  OF  ANTYLLUS  IV.  HUNTER'S  METHOD, 

V,  BRASDOR'S  METHOD.  VI.  WARDROP'S  METHOD. 

295 


LIGATIO.\S   OF  THE  ARTERIES.  297 

lower  vascular  pressure  and  allow  the  blood  to  begin  to  clot  in  the  aneurysm. 
Drills  which  lower  vascular  tension,  such  as  veratrum  viride  and  aconite,  should 
he  given  ;  and  iodid  of  jiotassiuin  administered  to  break  up  the  white  corpuscles 
and  liberate  the  librin  torment. 

Various  other  methods  of  treating  aneurysms  have  been  practised.  Among 
these  are  pressure,  ligature,  manipulation  of  the  aneurysm,  injection  of  coagulating 
materials,  introduction  of  foreign  bodies,  and  galvano-puncture. 

Pressure  applied  to  the  artery  to  the  proximal  side  of  the  sac  has  given  good 
results,  and  acts  by  checking  the  passage  of  blood  through  the  sac  and  allowing  it 
to  clot.  Digital  pressure  may  be  applied  by  relays  of  trained  assistants.  Its  feasi- 
bility, however,  is  limited  to  aneurysms  of  the  arteries  of  the  extremities,  as  the 
brachial,  superficial  femoral,  and  popliteal.  The  pressure  may  be  applied  more 
conveniently  by  means  of  tourniquets  which  do  not  interfere  with  the  return 
circulation. 

Ligatures  have  been  used  according  to  various  methods.  In  the  method  of 
Anh/Uus,  or  the  "old  operation,"  the  artery  was  tied  on  both  sides  of  the  aneurys- 
mal  sac.  The  sac- was  freely  exposed,  opened,  the  clot  turned  out,  and  the  artery 
tied  upon  either  side  of  the  sac.  This  is  not  a  good  operation  because  there  is 
copious  bleeding,  the  artery  is  tied  where  its  coats  aie  diseased,  and  consecutive  or 
secondary  hemorrhage  is  likely  to  occur.  This  method  is  the  one  commonly  prac- 
tised in  the  treatment  of  traumatic  false  aneurysms.  In  these  aneurysms  there  is 
not  the  same  objection  to  tying  the  artery  close  to  the  aneurysm,  since  the  walls  of 
the  vessel  are  not  necessarily  diseased  at  that  point. 

In  the  method  of  And  the  sac  is  exposed  and  the  artery  tied  immediately 
above  the  sac.  In  this  method,  as  in  that  of  Antyllus,  the  artery  is  tied  where  its 
coats  are  diseased. 

In  /,Y</x</o/.s'  method  the  main  trunk  of  the  artery  is  ligated  some  distance  to 
the  distal  side  of  the  aneurysmal  sac.  In  Wardrop's  method  one  or  more  of  the 
main  branches  of  the  artery  beyond  the  sac  are  tied.  These  two  methods  are 
applicable  in  aneurysms  at  the  root  of  the  neck,  as  of  the  innominate,  common 
carotid,  or  suhclavian. 

In  Hunter's  method  the  artery  is  tied  to  the  proximal  side  of  the  sac,  and 
where  the  coats  of  the  artery  are  sound,  as  in  Brasdor's  and  Wardrop's  methods  ; 
the  ligature  greatly  reduces  the  force  of  the  blood  current  and  allows  the  blood  to 
form  a  laminated  clot  in  the  sac.  Nature,  then,  has  an  opportunity  to  form  a  clot 
and  connective  tissue  within  the  sac,  and  obliterate  that  portion  of  the  artery. 
The  circulation  is  reestablished  by  enlargement  of  the  arteries  which  arise  above 
the  ligature  and  anastomose  with  those  which  arise  below  the  aneurysm.  This 
operation  is  performed  where  pressure  applied  to  the  artery  on  the  proximal  side 


298  SURGICAL   .-\.\.\TOMY. 

of  the  sac  is  not  feasible.  Pressure  upon  the  carotids  would  be  very  painful,  and 
therefore  Hunter's  method  is  used  in  preference  to  pressure  in  treating  aueiirvsm  of 
the  external  or  internal  carotid  or  upper  part  of  the  common  carotid. 

Manipulation  of  the  aneurysmal  sac  to  loosen  pails  of  the  fibrinous  clot 
from  its  wall  so  that  they  will  occlude  the  artery  to  the  distal  side  of  the  ancurysm 
is  a  dangerous  procedure,  because  embolism  or  rupture  of  the  sac  may  result. 
F.mliolism  from  manipulation  of  the  carotids  may  cause  hemiplegia. 

The  injection  of  coagulating  material,  such  as  neutral  ferric  chlorid  or  iibrin 
ferment,  may  be  practised  if  the  artery  is  compressed  on  both  sides  of  the  sac  for 
an  hour  or  more  during  the  injection.  There  is  much  danger  from  embolism, 
inflammation,  and  abscess. 

The  introduction  of  foreign  bodies,  such  as  fine  aseptic  wire,  favors  the 
formation  of  a  clot.  This  method  has  been  used  in  aortic  and  subclavian 
aiieurysms,  as  these  are  unfavorable  cases  for  ligature  or  pressure. 

Galvano-puncture  is  not  a  favorable  method  of  treating  aneurysms :  the  clot 
is  soft  and  therefore  uncertain,  inflammation  of  the  sac  and  its  contents  may 
follow,  and  the  eschar  at  the  point  of  introduction  of  the  needle  may  be  the 
site  of  secondary  hemorrhage. 

Anatomy  of  an  Artery. — The  wall  of  an  artery  is  composed  of  three  coats — 
an  internal,  a  middle,  and  an  external. 

The  internal  coat,  or  tunica  intima,  is  composed  of  a  layer  of  flat  endothelial 
cells  which  lines  the  vessel  wall,  and  an  elastic  layer  which  is  chiefly  composed  of 
yellow  elastic  fibers  arranged  in  a  mesh-work,  the  majority  of  the  fibers  of  which 
are  in  a  longitudinal  direction.  This  layer  is  united  to  a  layer  of  endothelial  cells 
by  delicate  areolar  tissue.  When  an  artery  is  ligatured,  the  internal  coat  curls 
inward  and  retracts,  thus  partially  occluding  the  lumen  of  the  artery  and  giving 
support  to  the  clot  of  blood  which  undergoes  organization.  When  an  artery  is 
completely  divided,  this  coat  curls  inward,  retracts,  and  contracts  in  the  same 
manner  as  when  it  is  ruptured  in  ligature  of  a  vessel. 

The  middle  coat,  tunica  media,  is  composed  chiefly  of  circular  muscular  and 
some  elastic  fibers.  The  muscular  fibers  predominate  in  the  smaller  vessels,  and 
the  elastic  tissue  in  the  larger  vessels.  When  an  artery  is  completely  divided,  it  is 
chiefly  through  this  coat  that  it  contracts,  while  retraction  is  produced  by  both  the 
internal  and  the  middle  coat. 

The  external  coat,  or  tunica  adventitia,  is  composed  chiefly  of  white  fibrous 
tissue,  and  some  longitudinal  elastic  fibers;  this  is  the  only  coat  of  an  artery 
which  is  not  ruptured  in  ligature  of  a  vessel. 

With  the  exception  of  the  mtra-cranial  arteries  and  the  ascending  portion  of 
the  arch  of  the  aorta,  all  arteries  are  covered  by  a  sheath  of  connective  tissue; 


PLATE  LXXVI. 


LINES  OF  ARTERIES  OF  UPPER  EXTREMITY  AND  OF  MEDIAN  AND   ULNAR  NERVES. 

300 


PLATE  LXXVII. 


LINES  OF  INCISIONS  FOR  LIGATION  OF  ARTERIES  AND  STRETCHING  OF  NERVES. 

301 


N  or  THI-:  AI;TI-:I;II-:S.  303 

mill  s( •  arteries,  such  as  the  common  carotid  and  common  femoral,  have  an 

additional  slicatli  formed  by  the  deep  fascia.  The  sheath  is  loosely  attached  to  the 
outer  coat  of  the  vessel  and  the  surrounding  structures,  and  gives  support  to  the 
vessel  \vall. 

When  ligating  an  artery,  it  is  customary  to  open  the  sheath  and  separate  it 
from  the  vessel  for  a  short  distance  before  passing  the  aneurysm  needle.  By  this 
procedure  unnecessary  pressure  upon  the  vasa  vasorum  and  increased  risk  of 
slouching  of  the  vessel  are  avoided.  Where  an  artery  has  two  sheaths,  the 
internal  as  well  as  the  external  sheath  must  be  opened. 

In  the  Ligation  of  Arteries  familiarity  with  the  following  rules  is  necessary  : 
The  ligature  must  not  be  placed  too  near  the  aneurysm  because  there  the  coats  of 
the  artery  are  diseased.  If  too  great  a  distance  intervene  between  the  aneurysm  and 
the  point  of  ligation.  the  collateral  circulation  is  too  quickly  established  and  blood 
passes  through  the  sac.  displaces  the  clot,  and  prevents  organization.  The  ligature 
must  not  be  too  near  a  large  branch,  as  the  current  of  blood  would  then  prevent 
clot  formation  and  organization  and  increase  the  risk  of  secondary  hemorrhage  when 
the  ligature  is  absorbed.  The  operator  must  be  well  acquainted  with  the  coin-so  and 
anatomic  relations  of  the  vessel,  with  its  anomalous  forms  and  relations,  and  its 
superficial  and  deep  landmarks.  The  incision  through  the  skin  and  tissues  over  the 
sheath  of  the  vessel  should  be  sufficiently  large  to  give  ample  room  for  the  applica- 
tion of  the  ligature.  As  soon  us  the  skin  and  fascia1  are  divided,  locate  the  anatomic- 
guides  to  the  artery  and  then  search  for  the  vessel,  the  pulsation  of  which  will  assist 
in  finding  it.  All  of  the  small  superficial  vessels  and  nerves  are  divided,  while 
large  ones  are  avoided  and  displaced.  Each  layer  of  tissue  over  the  vessel  is  carefully 
divided  so  that  the  anatomic  landmarks  may  not  be  lost.  The  cut  edges  of  the 
different  layers  are  separated,  but  separation  of  these  layers  is  avoided  as  much  as 
possible.  After  the  sheath  of  the  vessel  is  exposed  it  is  carefully  cleaned  for  a 
short  distance  and  a  small  portion  of  it  is  pinched  up  and  divided  with  the  knife 
held  flat  and  its  cutting  edge  away  from  the  vessel.  The  opening  in  the  sheath 
should  be  very  small.  After  the  sheath  is  opened  a  small  portion  of  it  is  suffi- 
ciently separated  from  the  artery  to  allow  the  aneurysm  needle  to  be  passed.  The 
separation  of  the  sheath  from  the  coat  of  the  vessel  is  most  important,  and  should 
be  done  with  the  back  of  the  knife  directed  toward  the  artery,  and  all  of  the  tissue 
removed  until  the  white  external  coat  is  seen.  The  sheath  should  be  separated 
from  the  artery  only  far  enough  to  allow  the  passage  of  the  needle,  because  too 
extensive  a  separation  of  the  sheath  from  the  vessel  increases  the  danger  of 
secondary  hemorrhage  by  division  of  the  vasa  vasorum  which  supply  that  part  of 
the  vessel. 

During  or  after  the  passage  of  the  needle  the  vessel  should  not  be  lifted  from 


:•><>- 1  $rj;<;lc.\l.   ANATOMY. 

its  position  ;  for  if  the  vasa  vasorum  be  torn,  tlie  danger  of  secondary  hemorrhage 
is  increased  by  preventing  nutrition. 

The  vasa  vasorum  should  not  be  ruptured  more  than  is  necessary  :  this  can  be 
prevented  if  the  operator  will  not  unnecessarily  separate  the  sheath  from  the  artery, 
nor  lift  the  vessel  from  its  original  position,  nor  depress  the  handle  of  the  needle, 
thereby  unnecessarily  elevating  the  artery.  The  needle  is  always  passed  away 
from  the  structure  which  would  be  most  endangered.  If  one  vein  accompanies 
the  artery,  the  needle  is  passed  away  from  the  vein  ;  if  the  artery  has  two  vena1 
comites  and  one  accompanying  nerve,  the  needle  is  passed  away  from  the  nerve. 
The  needle  may  he  passed  either  armed  or  unarmed.  Before  the  needle  is  with- 
drawn always  compress  the  artery  between  the  curve  of  the  needle  and  the  finger 
and  notice  if  the  pulsation  in  the  artery  or  its  branches  beyond  the  site  of  the 
operation  is  checked,  and  if  any  other  structures  are  included  in  the  ligature. 
The  ligature  should  always  be  tied  at  a  right  angle  to  the  course  of  the  artery  ; 
because  if  the  ligature  be  placed  obliquely,  it  is  apt  to  become  loose.  The  ligature 
is  tied  with  a  reef-knot,  or  a  surgical  knot,  firmly  enough  to  rupture  the  middle 
and  internal  coats  of  the  artery. 

The  undesirable  sequela*  of  ligature  of  an  artery  are  consecutive  hemorrhage 
from  loosening  of  the  ligature'  or  diseased  coats  of  the  vessel,  secondary 
hemorrhage  from  the  breaking  down  of  these  diseased  coats,  sloughing  around 
the  ligature  or  imperfect  organization  of  the  clot,  and  rupture  of  the  vessel.  Gan- 
grene of  the  limb  upon  the  distal  side  of  the  ligature  may  occur  because  of  tin- 
slow  and  insufficient  establishment  of  the  collateral  circulation.  Sloughing  of  the 
sac  may  result.  The  pulsation  in  the  sac  may  continue  or  return  after  having 
been  absent  :  because  the  ligature  was  placed  obliquely  and  became  loosened,  or 
was  placed  too  far  above  the  sac;  the  collateral  circulation  is  too  rapidly 
established  through  free  anastomosis  of  branches  above  and  below  the  ligature, 
or  because  of  the  presence  of  a  vas  aberrans. 

The  axillary  artery  begins  at  the  lower  border  of  the  first  rib,  and  extends  as 
far  as  the  lower  margin  of  the  tendon  of  the  teres  major  muscle.  With  the  arm 
abducted  to  a  right  angle  with  the  body,  the  course  of  the  artery  is  represented  by 
a  line  drawn  from  just  to  the  inner  side  of  the  middle  of  the  clavicle  to  the  middle 
of  the  bend  of  the  elbow.  The  artery  is  divided  into  three  parts  by  the  pectoralis 
minor  muscle.  The  first  part  lies  between  the  lower  border  of  the  first  rib  and  the 
upper  border  of  the  muscle  :  the  second  under  the  muscle,  and  the  third  between 
the  lower  border  of  the  muscle  and  the  lower  border  of  the  tendon  of  the  teres 
major.  As  a  rule,  the  axillary  artery  is  ligated  only  in  its  third  portion.  If  a 
higher  ligation  be  necessary,  it  is  generally  safer  to  ligate  the  third  portion  of 
the  subclavian  artery,  as  the  first  portion  of  the  axillary  artery  is  deeply  seated, 


LIGATIONS  OF  Tin-:  Aim-:uii->  or  TIII-:  UTTER  KXTHKMITY.     sos 

and  the  accompanying  vein  is  large.  prominent,  and  closely  connected  with  the 
co-to-coraeoid  ineinhraiie.  The  third  portion  of  the  axillary  artery  is  quite  acces- 
sible, he  ing  covered  for  a  short  distance  l>y  the  pectoralis  major  muscle,  beyond 
which  it  lies  just  beneath  the  skin,  superlieial  fascia  and  deep  fascia  when  the 
arm  is,  abducted.  In  front  of  the  third  portion  of  the  artery,  when  the  arm  is 
abducted,  are  the  peetoralis  major  muscle,  axillary  fascia,  inner  head  of  the  median 
nerve,  and  the  internal  cutaneous  nerve.  Ilehind  it  are  the  nxusculospiral  and 
circumflex  nerves,  the  subscapularis  muscle,  and  the  tendons  of  the  latissimus  dorsi 
and  teres  major  muscles.  On  the  inner  side  are  the  ulnar  nerve,  the  axillary  vein. 
and  the  lesser  internal  cutaneous  nerve  (nerve  of  Wrisberg) — the  latter  being  sepa- 
rated from  the  artery  by  the  vein.  On  the  outer  side  are  the  median  and  mnsculo- 
cutaneous (external  cutaneous)  nerves,  the  outer  of  the  veiue  comites  of  the  brachial 
artery,  and  the  coraco-brachialis  muscle.  The  branches  of  this  portion  of  the  artery 
are  the  subscapular,  anterior  circumflex,  and  posterior  circumflex.  In  ligating 
this  portion  of  the  axillary  artery  the  arm  should  be  carried  outward  to  a  right 
angle  with  the  body.  An  incision  is  made  in  the  line  of  the  vose],  beginning  at 
the  middle  of  the  floor  of  the  axilla.  It  is  then  carried  downward  about  three 
inches  along  the  inner  border  of  the  coraco-brachialis  muscle,  which  can  be  easilv 
felt.  The  skin  and  superficial  fascia,  with  small  branches  of  the  intercosto- 
humeral,  internal  cutaneous,  and  lesser  internal  cutaneous  nerves,  and  branches  of 
the  long  thoracic  artery,  are  divided.  The  deep  fascia  is  then  incised,  and  the 
inner  margin  of  the  coraco-brachialis  muscle  exposed.  The  coraco-brachialis  is 
drawn  outward,  and  the  position  of  the  artery  determined  by  its  pulsation.  The 
median  nerve  will  then  be  exposed,  and  should  be  drawn  outward,  while  the  inter- 
nal cutaneous  nerve  is  drawn  inward.  The  outer  of  the  vente  comites  of  the 
brachial  artery  and  the  axillary  vein  being  well  exposed,  the  ligature  can  be 
passed  around  the  artery  from  within  outward. 

The  unusual  forms  and  relations  of  the  axillary  artery  are  the  following : 
The  third  portion  of  the  artery  may  be  covered  by  a  muscular  slip  from  the 
latissimus  dorsi.  In  ten  per  cent,  of  cases  there  are  two  large  arterial  trunks 
instead  of  one;  one  of  them  may  be  a  common  trunk  of  origin  for  the  long 
thoracic,  subscapular,  posterior  circumflex,  and  superior  profunda  arteries,  while 
the  other  is  the  continuation  of  the  axillary,  and  continues  to  form  the  brachial ;  or 
one  of  the  trunks  ma}'  be  a  radial  or  ulnar  artery  with  an  unusually  high  origin. 
When  several  of  the  branches  of  the  axillary  arise  from  a  common  trunk,  as 
already  stated,  the  main  branches  of  the  axillary  plexus  may  surround  this  trunk 
and  therefore  be  useless  as  landmarks  for  locating  the  main  trunk  of  the  axillary 
artery. 

20 


:',()(•-  SURGICAL   ANATOMY. 

The  <;,lliiti'i-<il  circulation  after  ligature  of  the  third  part  of  the  axillary  artery 
above  the  origin  of  (lie  snhscapular  is  established  by  the  anastomosis  of — 

The    supra-scapular    and    acroniio-      ..,,    the    anterior  and  posterior  ehvuni- 
tlioraeic  ;i rt cries  Ilex  arteries. 

The  supra-scapular,  posterior  sea pu-     .-,,    the  dors:ilis  scapula.-  and  subscapu- 
lar  and  lonj:  thoracic  arteries  lar  arteries. 

The  intercostal  branches  of  the  aorta      .  , 

.  .  with  the  subscapular  artery. 

and  internal  mammary  artery 

When  the  arlerv  is  tied  l>ei ween  the  origin  of  the  subscapular  and  circumflex 
arteries,  the  collateral  circulation  is  established  l>y  the  anastomosis  of— 

The    supra-scapular    and    acroniio-      .  ,  the   anterior  and  posterior  circum- 
thoracic  arteries  ilex  arteries, 

and 

The  subscapular  artery  with  the  posterior  circumflex  artery. 

The  subscapular  artery. — The  arm  is  abducted  to  a  right  angle  with  the 
body,  and  the  artery  is  exposed  by  an  incision  made  through  the  floor  of  the  axilla 
along  the  anterior  border  of  the  posterior  fold  of  the  axilla.  The  skin,  superficial 
fascia,  superficial  vessels,  posterior  branches  of  the  lateral  cutaneous  nerves,  and  the 
axillary  fascia,  are  divided.  The  artery  is  found  to  the  inner  side  of  the  anterior 
border  of  the  latissimus  dorsi,  lying  in  the  areolar  tissue  in  front  of  the  subscapu- 
laris  muscle.  The  incision  should  avoid  the  axillary  vessels  which  are  upon  the 
outer  wall  of  the  axilla.  The  long  subsccqtular  nerve  lies  to  the  inner  side  of  the 
upper  one-third  of  the  artery  and  in  intimate  relation  with  the  middle  one-third. 
The  subscapular  n'm  lies  in  front  of  the  artery  at  its  origin,  and  holds  a  varying 
relation  to  the  remainder  of  the  artery.  The  <]<irx<ilix  xcd/mtu  <ui>-ri/  arises  from  the 
subscapular  artery  about  one  inch  from  the  origin  of  the  latter.  The  lower  xn/>- 
scapular  nerve  passes  toward  the  teres  major  muscle  just  above  or  below  the 
position  of  the  dorsalis  scapula?  artery. 

The  posterior  circumflex  artery  and  the  circumflex  nerve  are  most  readily 
found  upon  the  dorsal  surface  of  the  shoulder  as  they  emerge  from  the  quadrangu- 
lar space  to  supply  the  deltoid.  The  arm  is  abducted  to  a  right  angle  with  the 
body,  and  the  incision  is  made  along  the  posterior  border  of  the  deltoid.  The 
center  of  the  incision  should  be  at  the  angle  formed  by  this  border  of  the  deltoid 
and  the  axillary  border  of  the  scapula.  The  skin  and  fascia?  are  divided  and  the 
deltoid  is  drawn  forward.  The  long  head  of  the  triceps  and  the  lower  margin  of 
the  teres  minor  are  seen,  and  the  finger  may  be  introduced  into  the  wound  to 
detect  the  pulsation  of  the  artery  as  it  winds  around  the  surgical  neck  of  the 
humerus.  The  nerve  lies  upon  the  upper  side  of  the  artery.  The  quadrangular 


LIGATIONS    OF   THE   M!TE[UE*   »r   THE    UPPER    EXTHEMITY.       307 

space  is  bounded  upon  the  ouier  side  by  the  hunierus,  upon  the  inner  side  by 
the  long  head  of  (lie  triceps.  above  by  the  teres  minor,  and  below  liy  the  tercs 
major.  As  the  nerve  passes  through  the  space  it  supplies  a  branch  to  the  teres 
minor,  liranclies  to  (lie  deltoid,  and  gives  oif  cutaneous  branches  to  tlie  skin  over 
the  deltoid. 

The  brachial  artery  is  the  continuation  of  the  axillary  artery,  and  begins  at 
the  lower  edge  of  the  tendon  of  the  teres  major  muscle.  Its  course  is  on  the  same 
line  as  the  axillary  artery — namely,  from  just  to  the  inner  side  of  the  middle  of  the 
clavicle  to  the  middle  of  the  bend  of  the  elbow,  with  the  arm  at  a  right  angle  to 
the  body  ;  or  from  the  junction  of  the  anterior  one-third  with  the  middle  one-third 
of  the  outer  part  of  the  floor  of  the  axilla  to  the  middle  of  the  bend  of  the  elbow. 
The  artery  is  practically  subcutaneous  throughout  its  entire  extent;  except  in  the 
middle  of  its  course  where  the  median  nerve  lies  in  front  of  it  ;  and  at  its  lower 
end  where  the  bicipital  fascia  and  median  basilic  vein  are  in  front. 

In  front  of  the  artery  are  the  skin,  superficial  and  deep  fascia>,  inner  border  of 
the  coraco-brachialis  and  biceps  muscles,  the  median  nerve  at  the  middle  of  the 
arm,  the  median  basilic  vein,  internal  cutaneous  nerve,  and  bicipital  fascia  at  the 
bend  of  the  elbow.  Behind  it,  from  above  downward,  are  the  long  head  of  the 
triceps,  the  musculo-spiral  nerve,  the  superior  profunda  artery,  the  inner  head  of 
the  triceps,  the  insertion  of  the  coraco-brachialis,  and  the  brachialis  anticus  muscle. 
To  its  inner  side  are  the  ulnar  nerve  in  the  upper  half  of  the  arm,  the  internal 
cutaneous  nerve  and  the  basilic  vein  in  the  upper  two-thirds  of  the  arm,  and  the 
median  nerve  at  the  bend  of  the  elbow.  To  its  outer  side  are  the  coraco-brachialis 
and  biceps  muscles,  as  well  as  the  median  nerve  in  the  upper  part  of  the  arm,  and 
the  tendon  of  the  biceps  at  the  elbow.  Two  veins  accompany  the  artery,  one 
lying  on  each  side  of  it. 

The  artery  may  be  ligated  at  the  lend  of  tlie  elbow,  or  at  the  middle  of  the 
arm.  In  ligating  it  at  the  bend  of  the  elbow  the  arm  should  be  slightly  flexed  in 
order  to  make  prominent  the  tendon  of  the  biceps.  The  median,  median  basilic, 
median  cephalic,  and  deep  median  veins  usually  join  on  a  level  with  the  point 
where  the  tendon  ceases  to  be  felt  distinctly.  Having  located  these  points,  the 
forearm  should  be  extended  and  the  arm  abducted  and  allowed  to  rest  on  the 
olecranon.  An  incision,  about  two  inches  long,  is  made  along  the  inner  edge  of 
the  tendon  of  the  biceps ;  the  upper  end  of  the  incision  being  about  on  a  level 
with  the  tip  of  the  internal  condyle.  The  skin,  superficial  fascia,  the  anterior 
branch  of  the  internal  cutaneous  and  branches  of  the  external  cutaneous  nerve, 
twigs  from  the  inferior  profunda  and  anastomotica  magna  arteries,  with  their  veins, 
are  severed.  The  median  basilic  vein  will  be  found  lying  on  the  inner  side  of, 
and  parallel  with,  the  incision,  and  should  be  drawn  to  one  side  as  soon  as 


308  SURGICAL   ANATOMY. 

exposed.  Tin-  deep  fascia  and  bicipital  fascia  arc  divided  in  the  line  of  the 
original  incision,  and  the  artery  with  its  vena-  coinites  and  the  median  nerve, 
which  lies  to  its  inner  side,  exposed.  The  veins  should  be  separated  from  the 
artery,  its  sheath  opened,  and  the  ligature  passed  around  the  artery  from  within 
outward. 

Ligature  of  the  hrachial  artery  or  st  retell  ing  of  the  median  nerve  at  the  bend 
of  the  elbow  is  not  an  advisable  operation,  because,  if  possible,  scars  should  not  be 
made  at  tlexures  of  joints. 

In  ligating  the  braehial  artery  in  tin1  iitiildle  of  t}te  arm  the  incision  should  be 
made  along  the  inner  edge  of  the  biceps  muscle.  The  skin,  superficial  fascia, 
twigs  of  the  internal  cutaneous  nerve,  and  small  branches  of  the  superior  profunda 
and  anterior  circumflex  arteries  will  be  divided.  The  deep  fascia  is  then  incised 
and  the  inner  edge  of  the  biceps  muscle  clearly  demonstrated.  The  muscle  is 
displaced  outward,  and  the  position  of  the  artery  determined  by  its  pulsations. 
The  median  nerve  is  then  exposed,  generally  lying  over  the  artery  in  this  part  of 
its  course.  It  should  be  drawn  inward  and  the  sheath  of  the  vessel  opened. 
The  veiue  coinites  are  then  separated  from  the  artery,  and  the  ligature  passed 
from  within  outward  away  from  the  basilic  vein. 

After  ligature  of  the  braehial  artery  above  the  origin  of  the  superior  profunda 
artery  the  cnllntfi'iil  circulation  is  established  by  the  anastomosis  between  the 
posterior  circumflex  and  superior  profunda  arteries. 

In  ligating  the  braehial  artery  it  is  to  be  remembered  that  in  about  twenty 
per  cent,  of  all  cases  there  are  two  large  arteries  in  the  arm  instead  of  one.  This 
is  due  to  the  high  origin  of  either  the  radial  or  nlnar  artery,  or  to  the  presence  of  a 
vas  aberrans.  A  third  head  of  origin  of  the  biceps  sometimes  crosses  in  front  of  the 
braehial  artery  near  the  middle  of  the  arm.  The  median  nerve  is  frequently  under 
instead  of  over  the  middle  portion  of  the  artery.  The  braehial  artery  and  the 
median  nerve  rarely  pass  toward  the  posterior  surface  of  the  internal  condyle  ; 
they  pass  around  the  supra-condyloid  process  and  then  in  front  of  the  elbow.  This 
artery  is  most  readily  compressed  at  the  middle  of  the  arm  where  it  lies  upon  the 
coraco-brachialis  muscle;  it  is  usually  ligated  in  this  location. 

The  braehial  artery  is  sometimes  ligatured  for  an  arterio-venous  aneurysm. 
This  is  usually  caused  by  a  wound  which  involves  both  the  artery  and  the  adja- 
cent median  basilic  vein  or  venae  coinites,  but  may  occasionally  result  from 
disease.  Arterio-venous  aneurysms  are  of  two  varieties — aneurysmal  varix  and 
varicose  aneurysm.  In  an  aneu/rysmal  r<iri.r  the  wounds  of  the  artery  and  vein 
have  adhered  and  become  closely  united  by  inflammatory  exudate  ;  there  is  formed 
a  direct  connection  between  the  artery  and  the  vein,  and  the  arterial  blood  passes 
directly  into  the  vein,  each  pulsation  dilating  it  and  causing  regurgitation  through 


u<;. \no.\s  OF  nil-:  .\i:TEiiir.*  OF  mi-:  rri'Ki:  KXTI:I-:MITY.     309 

its  valves.  There  ensues  detention  and  a  varicose  condition  of  the  adjacent  super- 
fieial  and  deep  veins.  These  veins  heroine  elongated,  tortuous,  thickened,  and 
may  pulsate;  hut  a  characteristic  aneurysm  is  not  formed.  In  a  varicose  aneu- 
/•//.-•///  the  inflammatory  exudate  whicli  hinds  together  the  wounds  in  the  artery 
and  vein  has  yielded  and  a  sac  is  formed  by  dislenlioii  of  the  channel  which 
connects  the  two  vessels.  The  blood  passes  from  the  artery  through  the 
connecting  channel  and  its  sac  and  into  the  vein.  The  most  common  cause 
of  varicose  aneurysm  in  connection  with  the  hrachial  artery  is  venesection 
practised  upon  the  median  hasilic  vein,  which  crosses  the  hrachial  artery.  As 
the  vein  is  now  opened  with  a  bistoury,  anenry.smal  varix  as  the  result  of 
venesection  is  rare. 

Punctured  or  gunshot  wounds,  however,  may  cause  a  varicose  aneurysm.  In 
both  varieties  of  arterio-venous  aneurysm  there  is  pulsatile  dilatation  of  the  veins, 
a  thrill,  and  a  continuous  murmur.  The  murmur  is  heard  along  the  course  of  the 
veins  toward  the  heart.  In  the  varicose  form  a  murmur  may  he  detected  at  the 
position  of  the  sac,  and  there  is  always  a  thrill  synchronous  with  the  beat  of  the 
pulse, 

These  aneurysms  are  treated  by  ligating  the  artery  to  either  side  of  the  sac, 
injecting  coagulating  fluids,  compression,  galvano-puncture,  expectant  method,  and 
amputation.  Most  cases  should  be  treated  hy  ligature  of  the  artery  above  and 
below  the  sac;  the  chief  dangers  to  be  feared  are  hemorrhage  from  the  artery 
above  the  sac  and  gangrene  of  the  limb  below  the  ligature. 

After  ligature  of  the  brachial  artery  at  the  middle  of  the  arm  the  circulation 
is  reestablished  by  the  anastomosis  of  the — 

the  anastomotica  inagna,  radial  re- 
Superior  prof unda  artery  with         current,  and  interosseous  recur- 
rent arteries, 

the  anastomotica  niasrna,  anterior 

The  inferior  profunda  artery  with         ulnar   recurrent,    and   posterior 

ulnar  recurrent  arteries. 

After  ligature  of  the  brachial  artery  at  the  bend  of  the  elbow  the  circulation 
is  reestablished  by  the  anastomosis  of — 

The  superior  profunda  and  anasto-       ..,,      the    radial    recurrent    and    inter- 
motica  magna  arteries  osseous  recurrent  arteries, 

The  inferior  profunda  and  anasto-         .  ,      the   anterior    ulnar  recurrent   and 
motica  magna  arteries  posterior  ulnar  recurrent  arteries. 

The  course  of  the  radial  artery  in  the  forearm  is  represented  by  a  line  drawn 
from  the  middle  of  the  bend  of  the  elbow  to  the  radial  pulse,  just  to  the  inner 


:',10  SURGICAL   ANATOMY. 

Mile  of  the  base  of  the  styloid  process  of  the  radius.  In  the  upper  lialf  of  its 
course  it  is  covered  by  .skin  and  fascia1  and  the  SUpinator  longus  muscle;  but 
in  the  lower  half  by  the  skin  and  fascia-  only.  Behind  the  vessel,  from  above 
downward,  are  the  biceps  tendon,  the  supinator  hivvis,  the  insertion  of  tin- 
pronator  radii  teres.  the  radial  origin  of  the  llcxor  suhlhtiis  digitorum,  the  flexor 
longus  pollicis.  the  pronator  (|Uadratns,  and  the  lower  end  of  the  radius.  It  is 
Hanked  on  either  side  by  vena.'  comites,  which  communicate  in  numerous  places 
by  transverse  brandies.  In  the  middle  of  the  forearm  the  radial  nerve  lies  in 
relation  with  the  outer  side  of  the  artery. 

When  ligating  the  artery  in  (lie  lower  onc-tliinl  »f  the  forearm,  the  incision  is 
made  along  the  line  of  the  artery,  between  and  parallel  with  the  tendons  of  the 
supinator  longus  and  flexor  carpi  radialis  muscles.  In  order  to  avoid  the  origin  of 
the  superficial  radial  vein  the  incision  should  not  extend  lower  than  the  level  of 
the  tuberosity  of  the  scaphoid.  The  skin,  superficial  fascia,  twigs  of  the  musculo- 
cutaneous  and  radial  nerves,  and  small  branches  of  the  radial  artery  will  be 
divided.  The  deep  fascia  is  then  incised,  and  the  space  between  the  tendons 
plainly  seen.  After  the  ven;e  comites  have  been  separated,  if  possible,  the  artery 
is  exposed  and  the  ligature  passed  in  either  direction.  When  they  can  not  be 
separated,  they  should  be  included  with  the  artery  in  the  ligature. 

When  ligating  the  radial  artery  in  tJte  middle  of  the  forearm,  the  incision  is 
made  over  the  line  of  the  vessel.  The  skin  and  superficial  fascia  will  be  divided, 
together  with  twigs  of  the  musculo-cutancons  nerve  and  small  branches  of  the 
radial  artery.  The  deep  fascia  is  then  incised  and  the  supinator  longus  muscle 
exposed.  This  muscle  is  drawn  outward  and  the  vessel  located  by  its  pulsations. 
It  will  be  found  lying  upon  the  insertion  of  the  pronator  radii  teres  muscle.  The 
verne  comites  are  to  be  separated  from  the  artery,  and  the  ligature  passed  around 
the  latter  from  without  inward. 

In  ligating  the  radial  artery  in  tlie  upper  one-thin!  the  incision  is  made  over 
the  course  of  the  vessel.  The  skin  and  superficial  fascia  are  divided,  with  branches 
of  the  mnsculo-cutaneous  nerve  and  of  the  radial  artery.  At  times  some  of  the 
large  superficial  veins  of  the  forearm  which  are  divided  may  cause  considerable 
hemorrhage.  The  deep  fascia  is  incised,  and  the  space  between  the  supinator 
longus  and  the  pronator  radii  teres  muscles  opened  up.  The  radial  artery  will 
be  found  under  the  supinator  longus  muscle.  The  ligature  maybe  passed  from 
either  side. 

To  ligate  the  radial  artery  in  tlte  "anatomic  snuff  box"  carry  an  incision  in 
the  long  axis  of  this  triangular  interval,  midway  between  the  extensores  primi 
and  secundi  internodii  pollicis  tendons.  Divide  the  skin  and  superficial  fascia, 
avoiding  injury  to  the  radial  vein  and  the  branch  of  the  radial  nerve  supplying 


STRETCHING    OF   Till'.    NERVES   OF   Till:    r/'l'Hi;    EXTREMITY.       311 

the  thumb.  Next  divide  the  deep  lascia,  when  the  artery  with  its  veii;e  <-<>mites 
will  be  exposed. 

The  radial  artery  may  arise  from  the  braehial  artery  in  the  arm  or  from  the 
axillary  artery,  and  is  at  times  quite  superficial,  overlying  the  supinator  longus 
muscle. 

The  ulnar  artery  may  be  ligated  in  the  middle  or  lower  one-third  of  the  fore- 
arm ;  but  is  seldom  done  in  the  upper  one-third  because  <>f  the  deep  position  of  the 
artery  there.  The  upper  portion  of  the  ulnar  artery  describes  a  curve  inward,  to  the 
ulnar  side  of  the  forearm.  Its  lower  two-thirds  correspond  to  a  line  drawn  from  a 
point  midway  between  the  internal  eondyle  of  the  humerus  and  the  middle  of  the 
bend  nf  the  elbow  to  the  radial  .side  of  the  pisiform  bone.  The  forearm  should  be 
supinated,  and  an  incision  made  over  the  line  of  the  vessel,  just  to  the  radial  side 
of  the  tendon  of  the  flexor  carpi  ulnaris.  The  incision  divides  skin,  superficial 
fascia,  twi^s  of  the  cutaneous  branches  of  the  ulnar  nerve,  the  anterior  branch 
of  the  internal  cutaneous  nerve,  and  small  branches  of  the  ulnar  artery.  The  deep 
fascia  is  exposed  and  incised  and  the  tendon  of  the  flexor  carpi  ulnaris  brought 
into  view.  The  tendon  is  drawn  inward,  and  the  ulnar  vessels  exposed.  The 
sheath  of  the  vessels  is  generally  bound  to  the  flexor  profuudus  muscle  by  a  layer 
of  fascia,  which  must  bo  divided.  The  ulnar  nerve  will  be  found  near  the  artery, 
on  its  inner  side,  and  its  palmar  cutaneous  branch  in  front  of  the  vessel.  Displace 
the  ulnar  nerve  and  its  palmar  cutaneous  branch  inward.  Separate  the  venae 
comites  from  the  artery  and  pass  the  ligature  from  within  outward. 

The  ulnar  artery  occasionally  arises  from  the  braehial  artery  high  in  the  arm, 
or  from  the  axillary  artery.  When  it  has  a  high  origin,  it  usually  passes  over 
the  muscles  which  spring  from  the  internal  eondyle,  and  is,  therefore,  in  much 
danger  of  being  wounded,  ruder  the  circumstances  the  recurrent  and  common 
interosseous  branches  arise  from  the  continuation  of  the  braehial  artery. 

After  ligature  of  the  radial  or  ulnar  artery  the  collateral  rhrnliifinn  is  chiefly 
established  through  the  palmar  and  carpal  arches,  and  partially  through  the 
anastomosis  of  the  muscular  branches  of  the  two  vessels. 


STRETCHING  OF  THE  NERVES. 

In  stretching  the  main  branches  of  the  braehial  plexus  of  nerves  in  the 
axilla  the  arm  should  be  abducted  to  a  right  angle  with  the  body,  and  an  incision 
made  in  the  line  of  these  nerves.  With  the  arm  abducted  as  above  mentioned, 
this  line  is  drawn  from  just  the  inner  side  of  the  middle  of  the  clavicle  to  the 


312  SURGICAL   A.\AT(t.MY. 

middle  of  the  bend  of  the  elbow.  They  will  he  found  along  the  inner  edge  of  the 
coraco-brachialis  muscle,  in  company  with  the  third  portion  of  tlie  axillary  artery. 
The  incision  extends  from  tlie  middle  of  the  floor  of  the  axilla,  along  the  inner 
eil^e  of  the  coraco-brachialis  muscle  for  about  three  inches.  The  parts  divided 
will  include  the  skin,  superficial  fascia,  small  brandies  of  the  Lntercosto-humeral, 
internal  cutaneous  and  lesser  internal  cutaneous  nerves,  cutaneous  branches  of 
the  long  thoracic  artery,  and  of  the  superficial  external  mammary  artery  when 
present.  The  deep  fascia  is  then  incised,  and  the  inner  edge  of  the  coraco-brachialis 
muscle  exposed.  The  first  portion  of  the  axillary  vein  and  the  third  portion  of 
the  axillary  artery  will  next  be  located.  The  vein  lies  in  front  of  tlie  artery  with 
the  arm  in  this  position.  The  median  and  musculo-cutaneous  nerves  will  be 
found  on  the  outer  side,  the  ulnar  nerve  on  the  inner  side  of  the  artery,  and  the 
musculo-spiral  and  circumflex  nerves  behind  the  vessel.  The  musculu-spiral  and 
circumflex  nerves  can  be  readily  reached  by  drawing  the  coraco-brachialis  muscle 
and  the  brachial  artery  outward.  These  nerves  are  generally  stretched  in  the  arm 
separately. 

The  course  of  the  ulnar  nerve  in  the  lower  part  of  the  arm  corresponds  to  a 
line  drawn  from  a  point  on  the  inner  side  of  the  insertion  of  the  coraco-brachialis 
to  a  point  midway  between  the  internal  condyle  of  the  humerus  and  the  olecranon. 
To  expose  the  nerve  an  incision  should  be  made  along  its  course,  beginning  about 
three  inches  above  the  internal  condyle  and  extending  to  about  one-half  of  an  inch 
above.  The  skin  and  superficial  fascia  are  to  he  divided,  with  brandies  of  the 
internal  and  lesser  cutaneous  nerves,  and  small  branches  of  the  inferior  profunda 
and  anastomotica  niagna  arteries.  Next,  the  deep  fascia  should  be  incised,  thereby 
exposing  the  internal  intermuscular  septum  covering  the  inner  head  of  the  triceps 
muscle.  Now  incise  the  intermuscular  septum,  when  will  be  seen  the  inferior 
profunda  artery,  which  is  readily  located  by  its  pulsations,  and  the  ulnar  nerve 
lying  to  the  inner  side  of  the  vessel. 

The  median  nerve  may  be  stretched  at  any  part  of  its  course  in  the  arm. 
At  the  bend  of  the  el  how  an  incision  should  be  made  along  the  inner  edge  of  the 
biceps  muscle,  beginning  about  on  a  level  with  the  tip  of  the  internal  condyle 
of  the  humerus  and  extending  downward  for  about  two  inches.  The  skin  and 
superficial  fascia,  branches  of  the  internal  cutaneous  nerve,  and  small  branches 
from  the  anastomotica  magna  and  anterior  ulnar  recurrent  arteries  will  be  divided. 
The  median  basilic  vein  will  he  found  lying  on  the  inner  side  of,  and  parallel  with, 
the  incision,  and  should  be  drawn  to  one  side  as  soon  as  exposed.  The  deep  fascia 
and  bicipital  fascia  should  be  divided  in  the  line  of  the  original  incision  and  the 
brachial  artery  exposed.  The  median  nerve  will  be  found  on  the  inner  side  of  the 
artery. 


>"/•/,' /•;•/> '///AY/  or  riu:  NERVES  OF  THE  i'i>ri:n  EXTREMITY.     ::i:; 

The  point  of  elect i< in  lor  exposing  the  musculo-spiral  nerve  is  immediately 
above  the  external  condyle  of  the  humerus.  The  incision  is  made  parallel  with 
the  inner  margin  of  tlie  snpinator  longu.-  nuisele.  Skin  and  superficial  fascia 
Avill  ln>  divided,  with  cutaneous  twigs  of  the  nmscnlo-spirnl  nerve  and  superior 
profunda  artery.  The  deep  fascia  is  incised  in  the  line  of  the  original  incision, 
and  the  inner  bonier  of  the  supinator  longus  muscle  exposed.  At  the  hottoin 
of  the  interval  between  this  muscle  and  the  hrachialis  anticus  the  nerve  is 
found.  The  terminal  portions  of  the  superior  profunda  and  radial  recurrent 
arteries  are  in  relation  with  the  nerve  in  the  interval. 

To  expose  the  radial  nerve  just  above  the  middle  of  the  forearm,  an  incision 
should  he  made  in  the  line  of  the  radial  artery — namely,  from  the  middle  of 
the  bend  of  the  elbow  to  the  radial  pulse.  At  this  point  the  nerve  will  be  found 
on  the  outer  side  of  the  artery  ;  but  a  short  distance  lower  down,  the  nerve  will  be 
seen  to  leave  the  artery  and  pass  to  the  posterior  aspect  of  the  forearm  by  going 
beneath  the  tendon  of  the  supinator  longus  muscle.  The  incision  divides  the  skin, 
superficial  fascia,  twigs  of  the  anterior  branch  of  the  musculo-cutaneous  nerve  and 
of  the  anterior  branch  of  the  internal  cutaneous  nerve,  and  small  branches  of  the 
radial  artery.  The  deep  fascia  is  then  incised  and  the  supinator  longus  muscle 
exposed.  The  muscle  is  drawn  outward,  and  the  radial  artery  located  by  its 
pulsations.  The  radial  nerve  will  be  found  lying  along  the  outer  side  of  the 
artery. 

The  ulnar  nerve  is  best  exposed  in  the  forearm  by  an  incision  made  immedi- 
ately above  the  wrist,  to  the  outer  side  of,  and  parallel  with,  the  tendon  of  the 
flexor  carpi  ulnaris.  The  skin,  superficial  fascia,  twigs  of  the  anterior  branch  of 
the  internal  cutaneous  nerve,  and  a  few  small  cutaneous  arteries  and  veins  will  be 
divided.  The  deep  fascia  is  incised  and  the  tendon  of  the  flexor  carpi  ulnaris 
exposed.  This  tendon  should  be  drawn  inward,  and  the  ulnar  artery  located  by 
its  pulsations.  The  ulnar  nerve  will  bo  found  to  the  ulnar  side  of  the  artery. 

The  point  selected  in  stretching  the  median  nerve  in  the  forearm  is  immedi- 
ately above  the  wrist.  The  incision  should  be  made  parallel  with  the  ulnar  border 
of  the  tendon  of  the  flexor  carpi  radialis ;  or,  if  the  palmaris  longus  be  present, 
between  the  tendons  of  these  muscles.  The  skin,  superficial  fascia,  twigs  from  the 
anterior  branch  of  the  internal  cutaneous  nerve,  and  a  few  small  cutaneous  arteries 
and  veins  will  be  divided.  The  deep  fascia  is  incised  and  the  tendon  of  the 
flexor  carpi  radialis  exposed.  This  tendon  should  be  drawn  outward,  when  the 
nerve  will  be  seen  between  the  superficial  and  deep  set  of  flexor  tendons,  to  the 
radial  side  of  the  outermost  tendon  of  the  flexor  sublimis  digitorum.  The  median 
artery  accompanies  the  nerve.  At  times  this  vessel  is  of  considerable  size,  and 
assists  in  forming  the  superficial  palmar  arch  in  place  of  the  ulnar  artery. 


314  SURGICAL    AXATOMY. 

The  brachial  plexus  of  nerves  and  its  large  branches  are  stretched  fur  the 
relief  of  epileptiform  convul-ions  following  injury  ui'  tin-  plexus  or  one  oi 
branches;  in  epilepsy  with  a  definite  aura  beginning  in  the  upper  extremity  ;  in 
paralysis  agitans  following  a  nerve  injury  ;  fur  the  relief  uf  pain  ami  anesthesia 
in  anesthetic  leprosy  ;  and  fur  the  relief  of  pain  and  spasm  of  the  muscles  result- 
ing from  a  contusion  or  a  lacerated  wound  which  has  involved  a  nerve.  Stretch- 
ing of  the  involved  nerve  or  nerves  is  not  certain  to  afford  permanent  relief  in  any 
case,  hut  the  operation  is  mure  satisfactory  in  cases  of  irritation  or  sclerosis  of  the 
nerve  from  contusion  or  involvement  of  a  lacerated  wound  in  scar  tissue. 

Irritation  of  the  circumflex  nerve  causes  spasm  of  the  deltoid  and  teres  minor 
muscles,  and  pain  over  the  deltoid  and  upper  part  of  the  triceps  muscle.  Irrita- 
tion of  the  nuixciil't-x/iii-iil  nerve  produces  spasm  of  the  triceps  muscle,  radial  exten- 
sors, superficial  extensors,  and  deep  extensors,  and  pain  in  the  hack  of  the  arm, 
outer  side  of  the  arm  and  forearm,  radial  side  of  the  hack  of  the  hand,  and  in  the 
dorsal  surface  of  the  thumh,  of  the  index  finder,  of  the  middle  ringer,  and  of  the 
radial  side  of  the  ring  finger.  Irritation  of  the  median  nerve  causes  spasm  of  the 
pronator  radii  teres,  flexor  carpi  radialis,  palmaris  longus,  flexor  suhlimis  digi- 
torum,  flexor  longus  pollicis,  radial  side  of  flexor  profundus  digitorum,  pronator 
quadratus,  abductor  pollicis,  opponeiis  pollicis,  outer  head  of  flexor  hrevis  pollicis, 
and  the  two  radial  lumhricales  muscles,  and  pain  in  the  front  of  the  wrist,  palm 
of  the  hand,  and  anterior  surface  of  the  thumh.  of  the  index  finger,  of  the  middle 
finger,  of  the  radial  side  of  the  ring  finger,  and  in  the  back  of  the  middle  finger 
over  the  two  distal  phalanges.  Irritation  of  the  ulnar  iic/'n  causes  spasm  of  the 
flexor  carpi  ulnaris,  ulnar  side  of  flexor  profundus  digitorum,  palmaris  brevis, 
muscles  of  the  hypothenar  eminence,  the  two  ulnar  lumbricales,  interossei  muscles, 
adductor  pollicis,  and  the  inner  head  of  the  flexor  hrevis  pollicis  muscle,  and  pain 
in  the  ulnar  side  of  the  wrist,  palm,  and  back  of  the  hand,  and  in  the  palmar 
and  dorsal  aspects  of  the  little  finger  and  ulnar  side  of  the  ring  finger. 

Operation  upon  the  nerves  of  the  upper  extremity  in  tetanus,  tetany,  and 
athetosis  has  not  been  mentioned,  for  it  is  generally  conceded  that  little  or 
nothing  is  gained  by  this  procedure.  Primary  or  secondary  suture  of  any  of  the 
large  nerves  of  the  upper  extremity  may  he  required  after  solution  of  the  con- 
tinuity of  the  nerve. 


PLATE  LXXVIII. 


£-  £ 

(J     

15  .5 


—       rt      — 


C       g      ™ 


£ 

CL 


OPERATIONS  FOR  EXPOSURE  OF  THIRD  PART,  AXILLARY  ARTERY  AND  LARGE  BRANCHES  OF  BRACHIAL,  BRACHIAL 
ARTERY  AND   MEDIAN  NERVE  AT  MIDDLE  OF  ARM,  AND  ULNAR  NERVE  IN   LOWER  ONE-HALF  OF  ARM. 

316 


PLATE  LXXIX. 


Median  n. 


Skin 


Brachial  a. 


Coraco-brachialis  m. 
Short  head  of  biceps  m. 
Superficial  fascia 


External  vena  comes  of  brachial  a. 
Axillary  v. 

Subscapular  v. 


Teres  major  m. 
Internal  cutaneous  n.' 

Latissimus  dorsi  tendon 

Ulnar  n.1 
Musculo-spiral  n. 


Subscapular  a. 
.esser  internal  cutaneous  n. 
Subscapularis  m. 


THIRD  PORTION-AXILLARY  ARTERY  AND  LARGE  BRANCHES  OF  BRACHIAL  PLEXUS. 

317 


PLATE  LXXX, 


Biceps  m 


Basilic  v. 


Ulnar  n. 
Brachial  a. 


Internal  cutaneous  n. 
Median  n. 

Deep  fascia 

Superficial  fascia 
Skin 


BRACHIAL  ARTERY  AND  MEDIAN  NERVE  AT  MIDDLE  OF  ARM. 
319 


PLATE  LXXXI. 


Internal  intermuscular  septum 

Deep  fascia 
Superficial  fascia 
Skin 


Inferior  profunda  a. 
,Ulnar  n. 


Triceps  m. 


21 


DINAR  NERVE  IN  LOWER  HALF  OF  ARM. 
321 


PLATE  LXXXII. 


Suprascapular  ; 


Superior  intercostal  a. 


Posterior  scapular  a 


Acrcmio-thoracic  a. — 


Subclavian  a. 
Internal  mammary  a. 

Superior  thoracic  a. 
)\      y^  Long  thoracic  a. 

Vas  aberrans 
loracic  aorta 


Aortic  intercostal  a. 


-Radial  recurrent  a. 
-Posterior  ulnar  recurrent  a, 

-Posterior  interosseojs  recurrent  5 


DIAGRAM  OF  COLLATERAL  CIRCULATION. 
324 


PLATE  LXXXIII. 


Radial  recurrent  a. 
Radial  a. 

Posterior  interosseous  recurrent 
Postoi ior  interosseo'js  a 


Anterior  radial  carpal  a. 
Superficial  volae  a 


Dorsalis  pollicis  a. 
Posterior  radial  carpal  a 


Princeps  pollicis  a. 
Dorsalis  indicis  a 


Radialis  indicis  a 


Deep  palmar  arch 


Brachial  a. 


Ulnar  a. 

Anterior  ulnar  recurrent  ?. 
Posterior  ulnar  recurrent  a. 

Common  interosseous  a. 
Anterior  interosseous  a. 


Muscular  branches 


Anterior  ulnar  carpal  a. 
Posterior  ulnar  carpal  a. 


Deeo  branch  of  ulnar  a. 


Superficial  palmar  arch 


DIAGRAM  OF  COLLATERAL  CIRCULATION. 
325 


PLATE  LXXXIV, 


Deep  fascia 

Bicipital  fascia 
Biceps  tendon 


Superficial  fascia 
Deep  fascia 
Supinator  longus  m. 


Radial  n._ 
Radial  a. 


^^H 

' 

Rrarhial    a 

II 

% 

Vpnap  romitps 

Superficial 
Fascia 

Radial  a. 
Supinator  longus 
Venae  comites 

Inner  tendon  of  flexor  sublimis  digitoruin 


Venae  comites 


Pronator  radii  teres  m. 


Flexor  carpi  radialis  m. 


Flexor  carpi  radia'is  tendon 

Superficial  fascia 

Deep  fascia 

Flexor  carpi  ulnaris  tendon 

Ulnar  a. 

Posterior  carpal  a. 
Ulnar  n. 
Venae  comites 


BRACHIAL  ARTERY  AND  MEDIAN   NERVE  AT  ELBOW,   RADIAL  ARTERY  AND   RADIAL  NERVE  AT  MIDDLE  OF  FOREARM, 
RADIAL  ARTERY  IN  LOWER  THIRD  OF  FOREARM,  AND  ULNAR  ARTERY  AND  NERVE  ABOVE  WRIST. 

328 


PLATE  LXXXV, 


Skin 
Superficial  fascia 

Deep  fascia 


Bicipital  fascia 


Brachial  a. 
Biceps  tendon 


Median  n. 

Brachial  venae  comites 


BRACHIAL  ARTERY  AND  MEDIAN   NERVE  AT  ELBOW. 
329 


PLATE  LXXXVI. 


s 


Skin 

Superficial   fascia 

Deep  fascia 


Radial  a. 


Radial  venae  comites 


Pronator  radii  teres  m. 


Supinator  longus  m. 

Extensor  carpi  radialis  longior  m. 
Flexor  carpi  radialis  m. 
Radial  n. 


RADIAL  ARTERY  AND   NERVE  AT  MIDDLE  OF  EOREARM. 
331 


PLATE  LXXXVII. 


Skin 

Superficial  fascia 

Deep  fascia 


Radial  a. 
Radial  venae  comites 


Flexor  carpi  radialis  tendon 
Supinator  longus  tendon 

Extensor  carpi  radialis  longior 

tendon 


RADIAL  ARTERY  ABOVE  WRIST. 
333 


PLATE  LXXXVIII. 


Skin 
Superficial  fascia 

Deep  fascia 


Dinar  a. 

Ulnar  venae  comites 

Flexor  carpi  ulnaris  tendon 

Inner  tendon  of  flexor  sublimis 
digitorum  m. 

Ulnar  n. 


ULNAR  ARTERY  AND  ULNAR  NERVE  ABOVE  WRIST. 
335 


PLATE  LXXXIX. 


Extensor  primi  internodii  pollicls  tendon 

Extensor  secundii  internodii  pollicis  tendon 


Line  of  incision  for  radial  a. 
extensor  ossis  metacarpi  pollicis  tendon 


INCISION  FOR  RADIAL  ARTERY  IN  "SNUFF-BOX." 
337 


PLATE  XC. 


Radial 

Fxtenspr  secundi 
internodii  pollicis  tendon 


Branch  of  radial  n.< 
Deep  fascia 


Superficial  fascia 
Extensor  primi  internodii  pcliicis  tendon 


Extensor  ossis  metacarpi  pollicis  tendon 


Radial  a 


RADIAL  ARTERY  IN  "SNUFF-BOX." 
339 


PLATE  XCI. 


Circumflex  n. 
Posterior  circumflex  a. 
Posterior  circumflex  v. 


Superficial  fascia 


Deep  fascia 


Deltoid  m 


Teres  minor  m, 

Infraspinatus  m. 


Long  head  of  triceps  m 


POSTERIOR  CIRCUMFLEX  ARTERY  AND  CIRCUMFLEX  NERVE. 
341 


PLATE  XCII. 


Dorsalis  scapulae  a. 

Teres  major  m, 

Latissimu,s  dorsi  m 
Middle  or  long  subscapular  n 


ubscapular  a. 

Subscapular  v. 

—  Lower  subscapular  n. 

Subscapularis  m. 


Deep  fascia 
Superficial  fascia 


SUBSCAPULAR  ARTERY,  MIDDLE  AND  LOWER  SUBSCAPULAR  NERVES, 

343 


PLATE  XGIII. 


Superficial  fascia- 


Deep  fascia- 


Brachialis  anticus  m. 


Radial  recurrent  a.- 


Musculo-spiral  n. 


tor  longus  m. 


MUSCULO-SPIRAL  NERVE  ABOVE  EXTERNAL  CONDYLE  OF  HUMERUS, 

345 


PLATE  XCIV. 


Brachialis  anticus  m. 
Deep  fascia 
Superficial  fascia 
Skin 


Supinator  longus  m. 

Musculo-spira!  n. 


Radial  Recurrent  a, 


MUSCULO-SPIRAL  NERVE  ABOVE  EXTERNAL  CONDYLE  OF  HUMERUS. 

347 


PLATE  XCV. 


Superficial  fascia 


Median  a. 

Flexor  carpi  radialis 
tendon 

Palmar  cutan.br. of 
median  n. 


-  Skin 
-  Deep  fascia 

Palmaris  longus  tendon 
Flexor  sublimis  digitorum  m. 
Median  n. 


MEDIAN  NERVE  ABOVE  WRIST. 
349 


TIIK    H.K'K  OF  THE  .V/-.VA'.    SHOULDER,   AXD    TJtl'XK.  351 

Till:   BACK  OF   THE  NECK,    silorLDEH,   AM)   77,'f.VA". 

Surface  anatomy. — In  the  middle  line,  extending  from  tlir  external  occipital 
protuberance  1o  the  sacrum,  is  a  longitudinal  furrow,  especially  well  pronounced  in 
muscular  subjects  in  the  dorsal  and  lumbar  regions.  At  the  back  of  the  neck  it  is 
called  the  nuchal,  and  below  that  point  the  spinal,  furrow.  It  is  produced  by 
the  presence  of  large  muscular  masses  upon  each  side  of  the  median  line,  and  by 
the  close  adherence  of  the  fascia'  to  the  ligamentum  undue  and  the  supra-spinous 
ligaments.  In  the  neck  and  dorsal  region  this  groove  lies  between  the  trape/ius 
muscles,  and  in  the  lumbar  locality  between  the  erector  spina-  muscles.  The  spinal 
furrow  is  deepest  in  the  lower  dorsal  and  the  upper  lumbar  region  and,  asit  descends 
toward  the  sacrum,  where  the  erector  spina'  muscles  arc  more  tendinous,  gradually 
fades  away.  A  little  above  and  external  to  the  last  spinous  process  of  the  sacrum 
(third  sacral  spine)  is  a  depression  which  marks  the  position  of  the  posterior  supe- 
rior spine  of  the  ilium.  At  the  bottom  of  the  nuchal  furrow  the  bilid  spine  of 
the  axis,  and  less  distinctly  the  spines  of  the  third,  fourth,  and  iii'th  cervical  verte- 
brae, may  be  felt.  The  spines  of  the  sixth  and  seventh  cervical  vertebra?  stand 
out  prominently.  At  the  bottom  of  the  spinal  furrow  the  spinous  processes  of  the 
dorsal,  lumbar,  and  sacral  vertebra:  may  be  readily  distinguished  ;  they  become 
more  pronounced  when  the  body  is  bent  forward. 

The  scapula  can  be  outlined  at  the  back  of  the  shoulder  with  facility  in  thin 
persons  and  with  difficulty  in  obese  persons.  The  vertebral  border  of  the  bone  is 
felt  at  the  side  of  the  spinal  furrow,  and  with  the  arm  at  the  side  of  the  body  is 
parallel  with  the  spinous  processes  of  the  vertebras.  During  abduction  of  the  arm, 
the  inferior  angle  of  the  scapula  glides  forward  and  the  vertebral  border  makes  an 
increasing  angle  with  the  spinous  processes  of  the  vertebra?.  The  axillary  border 
is  indistinctly  felt,  and  the  superior  border  can  not  be  palpated  through  the  over- 
lying muscles.  AVhen  the  arms  are  hanging  by  the  side,  the  superior  angle  of  the 
scapula  is  opposite  the  upper  margin  of  the  second  rib,  and  the  inferior  angle  over- 
lies the  seventh  intercostal  space.  The  inferior  angle  is  a  guide  in  the  operations 
of  aspiration  or  drainage  of  the  pleural  sac,  which  are  performed  in  the  fifth  or 
sixth  intercostal  space  at  the  side  of  the  thorax.  The  spinous  and  acromion  pro- 
cesses of  the  scapulae  are  subcutaneous  and  readily  palpated,  so  that  fractures  of 
these  processes  are  detected  more  easily  than  fractures  of  other  portions  of  the 
scapula.  The  vertebral  extremity  of  the  spinous  process  is  opposite  the  spinous 
process  of  the  third  thoracic  vertebra,  and  the  outer  extremity  joins  the  acromion 
process.  The  acromial  angle  is  at  the  junction  of  the  lower  margin  of  the  spinous 
process  with  the  outer  margin  of  the  acromion  process.  From  this  angle  the 
length  of  the  upper  extremity  may  be  measured,  the  lower  points  selected  being 


•  \~>-2  SURGICAL    .  I. V.I  TO  MY. 

the  external  eondyle  of  the  humerusand  the  stylnid  process  of  the  radius,  or  the 
internal  eomlylc  of  the  humerus  and  the  styloid  process  of  the  ulna. 

Over  the  inner  end  of  the  spine  of  the  scapula  is  a  depression  which 
marks  the  position  of  the  flat,  triangular  tendon,  into  which  the  lower  libers 
of  the  trapt'/ius  muscle  are  inserted.  Above  the  spine  of  this  bone,  extending  to 
the  sloping  Mirfacc  of  the  shoulder,  is  a  rounded  elevation,  produced  by  the 
trape/.ins  resting  upon  the  levator  anguli  scapula-  and  supra-spinatus  muscles. 

When  the  patient  is  sitting  and  his  arms  hang  between  his  thighs  so 
as  to  depress  (he  scapula',  the  spines  of  those  bones  are  almost  opposite  the 
fissures,  between  the  upper  and  lower  lobes  of  the  lungs.  The  location  of  these 
fissures  is  of  importance  in  the  diagnosis  of  lobar  pneumonia. 

The  lower  ribs  can  be  felt  at  the  back  of  the  trunk,  external  to  the  erector 
spin.-i-  muscle.  As  the  twelfth  rib  does  not  always  extend  beyond  the  outer 
margin  of  the  erector  spina-  muscle,  the  ribs  should  be  counted  from  above 
downward.  Just  below  the  last  rib  and  external  to  the  erector  spime  muscle 
the  kidney  can  be  palpated  and  subjected  to  pressure. 

In  percussion  or  auscultation  at  the  back  of  the  chest,  the  patient  should  cross 
his  arms  and  lean  forward  so  that  the  scapula;  will  be  carried  forward,  and  uncover 
as  much  of  the  posterior  surface  of  the  chest  as  possible.  Because  of  the  presence 
of  thick  masses  of  muscular  tissue  in  the  vertebral  grooves,  there  is  at  all  levels 
dullness  on  percussion  close  to  the  spinous  processes  of  the  vertebrae. 

The  spines  of  the  vertebrae  lie  in  a  straight  line,  and  the  spinal  column 
presents  no  lateral  curves.  The  back,  like  the  spinal  column,  contains  four 
antero-posterior  curves — the  cervical,  thoracic,  lumbar,  and  pelvic.  The  cervical 
curve  of  the  spinal  column  is  convex  forward,  the  thoracic  curve  concave  forward, 
the  lumbar  curve  convex  forward,  and  the  pelvic  curve,  which  is  formed  by  the 
-acrum  and  coccyx,  concave  forward.  As  seen  in  viewing  the  surface  of  the 
back,  the  cervical  curve  is  concave  backward,  the  thoracic  convex  backward,  the 
lumbar  concave  backward,  and  the  pelvic  convex  backward. 

Disease,  overwork,  or  senility  may  alter  the  curves  of  the  spinal  column. 

Kyphosis,  or  fonvar<|  curvature  of  the  spine,  is  seen  in  rickety  children,  in  old 
persons,  and  in  laborers  who  do  heavy  work.  In  rickets  the  bones,  containing  less 
earthy  matter  than  in  health,  become  so  abnormally  flexible  that  the  weight 
of  the  head  bends  the  spinal  column  forward.  In  old  persons  and  in  laborers  the 
forward  curvature  is  caused  by  thinning  or  compression  of  the  intervertebral  discs. 

In  lordosis  the  lumbar  curve  is  exaggerated,  and  the  depression  in  the 
lumbar  region  of  the  back  is  increased.  This  condition  is  seen  in  persons  who,  to 
retain  their  equilibrium,  are  compelled  to  throw  the  shoulders  backward.  It  is 
observed  in  persons  whose  acetabula  and  hip-joints  are  situated  unusually  far 


PLATE  XCVI. 


SURFACE  MARKS  OF  BACK. 
353 


THE  BACK  OF  THE  XECK,   SHOULDER,   AXD    TRUNK.  355 

backward;  in  persons  who,  from  spinal  caries,  liavo  angular  forward  curvature  of 
the  upper  part  of  the  thoracic  region  of  the  spine  and  are  compelled  to  increase 
the  curve  of  the  lumbar  spine  on  account  of  the  advanced  position  of  the  head  and 
shoulders  ;  in  pregnant  women,  and  in  obese  persons. 

Lateral  curvature  of  the  spinal  column  in  children  is  caused  by  sitting  in 
one  position  for  a  long  time ;  by  an  unequal  length  of  the  lower  extremities,  which 
causes  lateral  inclination  of  the  pelvis,  and  by  empyema.  Lateral  curvature  of 
the  spinal  column  from  malposition  is  most  common  in  girls  who  have  less 
exercise  than  boys  and  who  are,  therefore,  more  easily  tired.  If  such  a  child  sit 
for  a  long  time  upon  a  seat  not  well  designed  for  comfort,  or  at  a  desk  which 
is  not  of  the  proper  height,  the  muscles  of  the  back  become  tired,  and  the  child 
curves  the  back  so  that  the  weight  will  be  supported  by  the  spinal  column 
without  much  assistance  from  the  muscles.  By  taking  the  child  from  school  and 
giving  her  plenty  of  muscular  exercise,  massage,  and  gymnastics,  and  avoiding 
uncomfortable  positions,  the  condition  is  corrected.  If  the  lateral  curvature  lie 
produced  by  a  short  leg,  a  thick  sole  on  the  shoe  of  that  leg  will  correct  the 
deformity  of  the  spinal  column.  The  most  common  condition  which  causes 
shortening  of  one  leg  is  hip  disease.  Nature  tilts  the  pelvis  to  compensate  for 
the  shortness  of  the  affected  limb,  and  laterally  curves  the  spinal  column  so 
that  equilibrium  may  be  maintained.  When  one  lung  is  permanently  collapsed 
as  a  result  of  empyema,  the  pulmonary  space  of  that  side  is  diminished,  the 
ribs  fall  together,  and  the  thoracic  portion  of  the  spinal  column  is  curved. 
Curvature  of  the  thoracic  portion  necessitates  compensatory  curvature  of  the 
lumbar  portion  of  the  spinal  column.  The  concavity  of  the  thoracic  and  the 
convexity  of  the  lumbar  curvature  are  directed  toward  the  affected  side.  In  the 
most  common  form  of  lateral  curvature  the  thoracic  region  of  the  spinal  column  is 
deflected  to  the  right  and  the  lumbar  region  to  the  left.  A  line  drawn  along  the 
tips  of  the  spines  of  the  vertebra)  would  be  curved  more  than  a  line  passing 
through  the  centers  of  the  bodies  of  the  vertebrae  ;  this  difference  is  due  to 
rotation  of  the  vertebra  so  that  the  tips  of  the  spines  extend  still  farther  in  the 
direction  of  the  convexity  of  the  curve.  When  the  lateral  curve  of  the  thoracic 
region  of  the  spinal  column  is  convex  to  the  right,  the  right  shoulder  is  elevated 
and  the  left  shoulder  depressed  ;  and  if  the  thoracic  region  be  deflected  toward  the 
left  side,  the  left  shoulder  is  elevated  and  the  right  shoulder  depressed. 

Angular  curvature  of  the  spinal  column  is  produced  by  caries  of  the 
vertebra.  In  this  disease  the  bodies  of  some  of  the  adjacent  vertebra  are  more 
or  less  disintegrated  by  tubercular  ulceration.  Removal  or  softening  of  the 
bodies  of  the  vertebra  allows  the  superimposed  weight  to  compress  the  bodies ; 
and  as  the  vertebral  arches  are  not  compressible,  the  affected  portion  of  the  spinal 


SURGICAL   . I.V. I  T<> MY. 

column  is  sharply  curved  forward  and  the  spinous  processes  of  the  involved 
vertebrae  project  backward. 

When  caries  of  the  vertebne  is  rapidly  progressing,  abscess  formation  occurs. 
These  pus  collections  are  called  cold  abscesses  because  ihey  are  not  associated  with 
heat  and  redness. 

In  disease  of  the  cervical  vertebrae  the  pus  accumulates  behind  the  pre- 
vertebral  fascia  and  the  pharynx,  forming  a  retro-pharyngeal  abscess,  which  causes 
bulging  in  the  posterior  pharyngeal  Avail,  and  difficulty  in  respiration  and 
deglutition.  It  may  rupture  into  the  pharynx,  gravitate  to  the  posterior  medias- 
tinum, or  burrow  outward  to  the  posterior  triangle,  of  the  neck,  and  even  enter  the 
axilla. 

In  caries  of  the  dorsal  vertebrae  the  pus  usually  gravitates  to  the  diaphragm, 
passes  under  the  internal  arcuate  ligament  and  the  psoas  fascia,  and  becomes  a 
psoas  abscess  ;  or  it  burrows  under  the  external  arcuate  ligament  and  the  anterior 
lamella  of  the  lumbar  fascia,  and  forms  a  lumbar  abscess.  The  pus  may,  how- 
ever, ulcerate  backward  between  the  ribs,  and  cause  a  swelling  in  the  back  ;  or  it 
may  follow  the  ribs  and  intercostal  muscles  forward,  and  produce  a  swelling  at  the 
side  or  front  of  the  chest.  Rarely,  one  of  these  abscesses  may  rupture  into  the 
esophagus,  pleura,  lung,  or  pericardium. 

In  caries  of  the  lumbar  vertebrae  the  pus  usually  enters  the  sheath  of  the 
psoas  muscle,  and  forms  a  psoas  abscess.  It  gravitates  downward  under  the  psoas 
division  of  the  iliac  fascia.  After  passing  under  Poupart's  ligament  it  produces  a 
swelling  at  the  outer  side  of  the  femoral  sheath,  where  the  psoas  and  the  iliacus 
muscles  approach  the  surface,  from  a  common  tendon,  and  occupy  a  common 
fascial  compartment.  These  abscesses  may,  however,  ulcerate  through  the  iliac 
fascia  and  open  into  the  peritoneal  cavity,  the  ascending  or  descending  colon  or 
other  portions  of  the  bowel,  the  ureter,  or  the  bladder.  The  pus  sometimes  passes 
under  the  anterior  lamella  of  the  lumbar  fascia  into  the  sheath  of  the  quadratus 
lumbomm  muscle,  and  forms  a  lumbar  abscess.  This  abscess  may  ulcerate 
through  the  middle  and  posterior  lamellae  of  the  lumbar  fascia  and  into  the 
triangle  of  Petit,  and  produce  a  swelling  near  the  middle  of  the  crest  of  the  ilium. 
From  this  description  it  may  be  understood  how  caries  of  the  upper  regions  of  the 
spinal  column  may  produce  a  lumbar  or  a  psoas  abscess. 

The  spines  of  the  vertebrae  may  be  used  as  landmarks  in  locating  various 
structures.  It  should  be  remembered,  however,  that  the  tips  of  the  spinons 
processes  in  the  thoracic  region,  with  the  exception  of  the  eleventh  and  twelfth, 
are  not  opposite  the  bodies  of  the  corresponding  vertebra?. 

The  sixth  cervical  spine  is  situated  opposite  the  cricoid  cartilage  and  the 
commencement  of  the  esophagus. 


PLATE  XCVII, 


Lordnsis. 


Normal  curve. 


Kyphnsis.          Lateral  curvature. 


358 


PLATE  XCVIII. 


/&/-y2/  Lumbar  caries 
Normal  Curve  Effaced 


Normal  Curve 


Advanced darsi- Lumbar 
tariEs  Angular  Curvature. 


359 


THE  BACK   OF   THE  XECK,   FlfOCLDKIt,    AND    TJ!f\k'.  W] 

The  serf nt li  cervical  spine  corresponds  to  tho  liigliost  level  of  the  apices  of  the 
lungs. 

The  tliird  thoracic  spine  lies  opposite  the  point  where  the  aorta  approaches 
the  spinal  column,  the  highest  level  of  the  lower  lobes  of  the  lungs,  and  the 
bifurcation  of  the  trachea. 

The  fourth  l/ioi-iteic  spine  is  located  opposite  the  point  of  termination  of  the 
arch  of  the  aorta  and  the  highest  level  of  the  heart. 

The  eighth  thoracic  spine  marks  the  lowest  level  of  the  heart  and  the  level 
of  the  central  tendon  of  the  diaphragm. 

The  ninth  thoracic  spin/'  marks  the  level  of  the  cardiac  orifice  of  the  stomach 
and  the  upper  limit  of  the  spleen. 

The  fcntJi  (Jioracic  spin/.'  locates  the  lowest  level  of  the  bases  of  the  lungs 
and  the  level  at  which  the  liver  reaches  the  abdominal  walls  posteriorly. 

The  eleventh  thoracic  x/nne  locates  the  lower  limit  of  the  spleen,  the  position 
of  the  supra-renal  capsule,  and  the  upper  border  of  the  right  kidney. 

The  twelfth  thoracic  spine  is  on  a  level  with  the  lowest  part  of  the  pleurae, 
the  aortic  opening  of  the  diaphragm,  and  the  pylorus. 

The  spine  of  the  first  hnn/x/r  rerteln-n  is  situated  opposite  the  renal  vessels,  the 
pelvis  of  the  ureter,  and  the  pancreas. 

The  second  linn/xir  spine  lies  opposite  the  end  of  the  spinal  cord,  the  third 
portion  of  the  duodenum,  and  the  receptaculum  chyli. 

The  third  lumbar  spine  is  found  just  above  the  level  of  the  umbilicus  and 
below  that  of  the  lower  border  of  the  right  kidney. 

The  fourth  lumbar  spine  is  located  opposite  the  bifurcation  of  .the  aorta  and 
the  highest  part  of  the  crests  of  the  ilia. 

The  fifth  lumbar  spine  marks  the  origin  of  the  inferior  vena  cava. 

The  third  sacral  spine  lies  opposite  the  termination  of  the  sigmoid  flexure  and 
the  lowest  level  of  the  spinal  membranes. 

The  tip  of  the  coccyx  marks  the  junction  of  the  first  and  second  portions  of  the 
rectum. 

The  origins  of  the  spinal  nerves  will  not  be  found  opposite  their  corre- 
spondingly numbered  vertebra?,  but  as  follows  :  The  eight  cervical  nerves  arise  above 
the  sixth  cervical  spine,  the  upper  six  thoracic  nerves  between  the  sixth  cervical 
and  fourth  thoracic  spines,  the  lotrer  six  thoracic  nerves  between  the  fourth  and 
eleventh  thoracic  spines,  the  five  lumbar  nerves  between  the  eleventh  and  twelfth 
thoracic  spines,  and  the  five  sacral  nerves  between  the  last  thoracic  and  first 
lumbar  spines. 

The  positions  of  the  primary  bronchi  are  indicated  by  lines  extending  from 
the  third  thoracic  spine,  or  a  point  a  little  below  it,  to  the  dimple  in  the  skin 


oii-J  SURGICAL   AXATOMY. 

over  the  mot  of  the  spine  of  the  scapula.  Sounds  are  heard  more  dearly  hi  the 
right  bronchus  because  it  lies  nearer  the  hack  of  the  chest. 

The  kidneys  are  Mtuated  opposite  the  lower  two  ribs,  with  their  inferior  ends 
projecting  below  the  twelfth  ril>:  1<>  ascertain  if  any  tenderness  exist  in  the  diseased 
organ,  pressure  may  be  made  upon  it  just  under  the  last  ril>,  external  to  the  erector 
spin.-e  muscle.  This,  too,  is  the  site  selected  when  operating  for  removal  of.  and  in 
exploratory  operations  upon,  the  kidney  through  the  hack.  The  right  kidney 
is  lower  than  the  left,  more  than  half  of  it  projecting  below  the  last  rib. 

The  iliac  crest  at  its  highest  point  is  located  about  opposite  the  fourth  lumbar 
spine. 

The  external  surface  of  the  spleen  is  directed  outward  and  backward.  This 
organ  lies  beneath  the  ninth,  tenth,  and  eleventh  ribs,  from  which  it  is  separated 
by  the  peritoneum,  diaphragm,  the  lower  portion  of  the  left  lung,  and  the  two 
layers  of  the  left  pleura.  It  holds  an  oblique  position;  its  long  axis  almo-t 
corresponding  to  the  line  of  the  tenth  rib. 

To  either  side  of  the  spinal  furrow  in  the  upper  part  of  the  back  are  the 
scapulae,  or  shoulder  blades,  covered  by  the  trapezius,  deltoid,  supra-spinatus, 
infra-spinatus,  and  latissimtts  dorsi  muscles.  The  scapula?  cover  the  ribs  from  the 
second  to  the  seventh  inclusive.  The  parts  of  the  scapula  most  readily  felt  are  the 
spine  and  the  acromion  process,  both  of  which  are  subcutaneous.  The  position  of 
the  acromion  is  marked  by  a  depression  when  the  arm  is  elevated,  and  in  muscular 
subjects  with  the  arm  hanging  loosely. 

At  the  junction  of  the  outer  border  of  the  acromion  with  the  lower  border  of 
the  spine  is  found  the  acromial  angle,  from  which  point  measurements  are  taken 
to  determine  the  comparative  lengths  of  the  upper  extremities.  At  the  inner  end 
of  the  spine  of  the  scapula  is  a  depression  which  corresponds  to  the  triangular 
tendon  into  which  the  lower  fibers  of  the  trapezius  muscle  are  inserted. 

The  sloping  superior  surface  of  the  shoulder  is  formed  by  the  trapezius  which 
covers  the  supra-spinatus  and  levator  anguli  scapula1  muscles. 

The  inferior  angle  of  tin-  «•«/<«/"  lies  opposite  the  seventh  intercostal  space,  and 
therefore  constitutes  a  landmark  in  locating  the  seventh  rib.  This  angle  is  covered 
by  the  latissimus  dorsi  muscle,  which  assists  in  holding  the  bone  against  the  chest 
wall.  Projection  of  this  angle  and  of  the  vertebral  border  of  the  bone  results  from 
atrophy  of  the  muscle  covering  it  and  of  the  serratus  magnus,  as  in  emaciated 
individuals.  This  deformity  is  known  as  "winged  -scapula,"  and  is  produced  by 
paralysis  or  weakness  of  the  serratus  magnus  and  latissimus  dorsi  muscles.  One 
of  the  functions  of  these  muscles  is  to  retain  the  vertebral  border  of  the  scapula 
in  contact  with  the  chest,  and  hence  when  it — either  or  both — is  paralyzed  this 
abnormality  follows.  The  vertebral  border  of  the  scapula  can  be  traced  upward 


PLATE  XCIX. 


RELATION  OF  VISCERA  OE  THORAX  AND  ABDOMEN  TO  BONY  PROMINENCES  OF  BACK. 

363 


PLATE  C. 


INCISIONS  FOR   DISSECTION. 
365 


THE   HACK   01-'   Till-    NECK,    tllon.DElt,    AM)    7'AT.VA'.  :\(\~ 

from  the  inferior  angle,  ami  wilh  Hie  arm  hanging  by  the  side  of  the  body  is 
nearly  parallel  to  the  spinal  furrow.  At  the  upper  extremity  of  this  border 
the  superior  <//////<•  of  the  seapnla  ean  be 'distinguished.  With  the  arm  at  the 
side  of  the  body  the  superior  angle  of  the  scapula  is  opposite  the  upper  border 
of  the  second  rib  and  on  a  level  \vith  the  interval  between  the  spines  of  the 
iirst  and  second  thoracic  vertebra-.  The  superior  />»r<l' r  of  the  scapula  can 
but  seldom  be  felt,  on  account  of  the  thickness  of  the  overlying  muscle.  The 
iij'itfttri/  I  in  fil  1 1'  of  the  scapula  can  be  indistinctly  felt  through  its  thick  muscular 
covering. 

The  mor<  inf  ntxuf  the  scapula  are  those  of  gliding  upward  and  downward,  as 
in  shrilling  the  shoulders;  backward  and  forward,  as  in  moving  the  shoulders  in 
those  directions;  and  a  gliding  rotatory  motion,  as  when  the  arm  is  fully  abducted. 
These  movements  are  best  studied  in  the  living  subject.  On  account  of  the  great' 
mobility  of  the  scapula  ankylosis  ()f  the  shoulder-joint  does  not  occasion  so  much 
disability  as  might  be  expected.  In  physical  examination  of  the  chest  poste- 
riorly the  patient  should  fold  the  aims  across  the  chest,  in  order  to  bring  the 
seapuhe  forward  and  uncover  as  much  of  the  chest  wall  as  possible. 

The  ribs  should  always  be  counted  from  above  downward,  as  the  twelfth  rib 
may  not  project  beyond  the  outer  margin  of  the  erector  sphue  muscle  and  therefore 
will  not  be  felt  distinctly. 

DISSKCTION. — Place  the  body,  face  downward,  upon  the  table,  with  a  block 
under  the  chest  and  one  under  the  pelvis  so  as  to  curve  the  back  and  permit 
the  head  to  hang  low  enough  to  make  the  structures  of  the  back  tense.  The 
arms  should  be  allowed  to  hang  over  the  sides  of  the  table  to  make  the  structures 
between  the  shoulders  tense.  Carry  an  incision  from  the  external  occipital  protub- 
erance down  the  median  line  of  the  back  to  the  sacrum.  From  the  upper  end  of 
this  incision  make  another  outward  over  the  superior  curved  line  of  the  occipital 
bone.  Make  a  third  incision  from  the  acromion  over  the  spine  of  the  scapula 
to  the  first  incision;  and,  lastly,  one  from  the  lower  end  of  the  longitudinal  cut 
along  the  sacro-iliac  junction  and  over  the  crest  of  the  ilium.  Reflect  the  segments 
of  skin  outward ;  the  superficial  fascia  will  then  be  exposed,  with  its  vessels  and 
nerves,  all  of  which  are  small. 

In  the  back  of  the  neck  and  upper  part  of  the  back  the  arteries  and  nerves 
appear  at  the  side  of  the  vertebral  spines  near  the  middle  of  the  back  and  extend, 
mainly,  outward.  The  arterial  blood  of  the  back  of  the  neck  is  derived  from  the 
occipital,  the  princeps  cervicis,  the  posterior  scapular,  and  the  superficial  cervical 
arteries;  of  the  back  of  the  shoulder  and  upper  part  of  the  back  from  the  pos- 
terior scapular,  supra-scapular,  dorsal  is  scapula?,  and  intercostal  arteries  ;  and  of  the 
middle  and  lower  part  of  the  back  from  the  posterior,  or  dorsal,  branches  of  the 


368  SUL>< ;!<'.[  I,   ANATOMY. 

intercostal    and    lumbar  arteries.      Branches  of  the  posterior  primary  divisions  of 
the  spinal  nerves  furnish  the  nerve  supply. 

The  posterior  primary  branches  of  the  spinal  nerves,  with  the  exception  of 
the  first  cervical  nerve  (suboccipital),  the  fourth  and  fifth  sacral,  and  the  coiw- 
geal  nerves,  divide  into  external  and  internal  branches:  each  primary  branch 
supplii  -  sensory  fibers  to  the  skin  in  each  region  of  the  back.  Both  the  external 
and  internal  branches  supply  nerves  to  the  muscles  of  the  back. 

The  external  branches  in  the  cervical  region  supply  the  muscles,  while  the 
internal  brandies  of  the  second,  third,  fourth,  and  fifth  nerves  supply  the  skin, 
fascia>,  and  muscles.  The  internal  branch  of  the  posterior  division  of  the  second 
cervical  nerve,  the  great  occipital,  pierces  the  complexus  and  trapezius  muscles 
and  ramifies,  with  the  occipital  artery,  in  the  superficial  fascia  of  the  back  of 
the  scalp.  The  internal  branches  of  the  third,  fourth,  and  fifth  cervical  nerves, 
after  supplying  the  adjacent  muscles,  pierce  the  trape/.ius  muscle  near  the  liga- 
mentum  nuchau  and  pass  outward  to  supply  the  skin  and  fascia'  over  that  muscle. 
The  internal  branch  of  the  third  cervical  nerve  is  directed  toward  the  scalp, 
and  is  called  the  smallest  or  third  occipital  nerve.  The  branches  of  the  sixth, 
seventh,  and  eighth  cervical  nerves  supply  the  adjacent  muscles. 

In  the  tlinrncic  rcf/imi  the  external  branches  of  the  posterior  divisions  of  the 
upper  six  thoracic  nerves  supply  the  muscles,  while  the  same  branches  of  the 
lower  six,  after  supplying  the  muscles,  pierce  the  latissimus  dorsi  near  the  angles 
of  the  ribs  to  furnish  nerves  to  the  skin.  The  internal  branches  of  the  posterior 
divisions  of  the  upper  six  thoracic  nerves  supply  the  muscles  of  the  back,  and 
pierce  the  trapezius  near  the  spinous  processes  to  supply  the  skin.  The  internal 
branches  of  the  lower  six  thoracic  nerves  supply  the  muscles,  and  send  small  twigs 
to  the  skin. 

The  external  branches  of  the  posterior  divisions  of  the  first  three  lumbar 
nerves  supply  the  adjacent  muscles,  become  subcutaneous  at  the  outer  border  of 
the  erector  spins?,  and  pass  over  the  crest  of  the  ilium  to  supply  the  skin  of  the 
gluteal  region  ;  the  corresponding  branches  of  the  fourth  and  fifth  lumbar  nerves 
supply  the  erector  spins;  muscle.  The  internal  branches  of  the  posterior  division 
of  the  lumbar  nerves  are  small ;  they  supply  the  multiiidus  spins1  muscle. 

The  posterior  primary  divisions  of  the  upper  four  sdc/'nl  m'rrrx  emerge  at  the 
posterior  sacral  foramina,  while  the  posterior  division  of  the  fifth  emerges  between 
the  sacrum  and  coccyx. 

The  posterior  divisions  of  the  upper  three  sacral  nerves  divide  into  external 
and  internal  branches,  while  the  lower  two  sacral  and  the  coccygeal  nerves  do  not 
divide.  The  external  branches  of  the  posterior  divisions  of  the  upper  three 
sacral  nerves  form  loops  upon  the  back  of  the  sacrum  between  themselves  and  the 


PLATE  Cl. 


24 


CUTANEOUS  NERVES  OF  BACK 
369 


THK  r>.«-K  <>r  Tin-:  .YAY-A',  SJIOL'I.DKK,  AXD  TRUXK.          ;::i 

external  branch  of  (he  last  lumbar  nerve,  and  upon  the  posterior  surface  of  the 
great  saero-sciat  ie  ligament  form  a  secoml  series  of  limps.  From  these  loops  are 
derived  two  or  three  nerves  which  pierce  the  glutcus  maximus  to  supply  the 
integument.  The  internal  branches  of  the  posterior  divisions  of  the  upper  three 
sacral  nerves  supply  the  multilidus  sphue  muscle.  The  posterior  divisions  of 
the  lower  two  sacral  nerves  form  loops  with  the  coccygeal  nerve,  and  the 
posterior  branch  of  the  third  sacral.  Branches  from  these  loops  supply  the 
skin  over  the  coccyx. 

Cutaneous  nerves. — The  skin  of  the  back  is  supplied,  in  the  ccrrical  r<<//<n>. 
by  the  internal  brandies  of  the  posterior  divisions  of  the  second,  third,  fourth,  and 
fifth  cervical  nerves;  in  the  tlnn-m-ii-  ,->  >/!<>,>  by  the  internal  branches  of  the  posterior 
divisions  of  the  upper  six  thoracic  nerves,  and  the  internal  and  external  branches 
of  the  posterior  divisions  of  the  lower  six  thoracic  nerves;  in  the  linubur  ra/imi. 
by  the  external  branches  of  the  posterior  divisions  of  the  upper  three  lumbar 
nerves;  over  the  sari-um  and  coccyx,  by  the  external  branches  of  the  posterior 
divisions  of  the  last  lumbar  nerve,  upper  three  sacral  nerves,  the  posterior  divisions 
of  the  lower  two  sacral  nerves,  and  by  the  coccygeal' nerve. 

The  cutaneous  nerves  are  accompanied  by  the  cutaneous  branches  of  the 
dorsal  branches  of  the  intercostal  and  lumbar  arteries. 

DISSECTION. — The  superficial  fascia  is  to  be  reflected  after  making  incisions 
similar  to  those  made  in  the  removal  of  the  skin. 

The  deep  fascia,  dense  and  fibrous,  invests  the  superficial  muscles  of  the  back 
(trapeziua  and  latissimus  dorsi).  It  is  continuous  with  all  the  adjacent  deep  fascia', 
and  is  attached  to  the  following  bony  prominences  of  the  back :  The  spines  of 
the  vertcbne  with  the  intervening  supra-spinous  ligaments,  the  sacrum,  the  iliac 
crests,  spines  of  the  scapula-,  and  the  superior  curved  ridges  of  the  occipital  bone. 
In  the  lumbar  region  the  deep  fascia  blends  with  the  glistening  triangular 
aponeurosis  of  the  latissimus  dorsi  muscle,  which  aponeurosis  extends  from  the 
iliac  crest  and  sacrum  as  high  as  the  spine  of  the  seventh  thoracic  vertebra. 
This  aponeurosis  should  be  preserved,  as  it  constitutes  the  superficial,  or  posterior, 
layer  of  the  lumbar  fascia.  The  aponeurosis  of  the  latissimus  dorsi  muscle  is 
pierced  at  the  outer  border  of  the  erector  spinse  muscle  by  cutaneous  branches 
of  the  posterior  divisions  of  the  lumbar  nerves. 

DISSECTION. — The  superficial  layer  of  the  deep  fascia  is  to  be  reflected  after 
making  incisions  similar  to  those  made  in  removing  the  skin  and  superficial  fascia. 
This  exposes,  in  the  neck,  the  trape/ius  muscle,  with  the  occipital  triangle,  and  the 
sterno-cleido-mastoid  muscle  on  its  outer  side ;  at  the  level  of  the  shoulders  the 
trapeziua  muscle,  spine  of  the  scapula,  deltoid  and  teres  major  muscles,  the  infra- 
spinous  fascia  which  covers  the  infra-spinatus  and  teres  minor  muscles  ;  below  the 


:'>7-2  SURGICAL    .I.V.I  TOMY. 

level  of  the  shoulders,  the  lower  part  of  the  Irapc/.ius  muscle,  the  latissimus  dorsi 
and  its  aponeurosis,  and  the  posterior  lihevs  of  (lie  external  and  internal  oblique 
muscles. 

The  trapezius  is  a  hrond,  flat  muscle,  triangular  in  outline,  with  the  bast  of 
the  triangle  directed  toward  the  spines  of  the  vertebr;e  and  the  apex  toward  the 
summit  of  the  shoulder.  It  is  one  of  the  most  extensive  muscles  of  the  body.  It 
arises  from  the  inner  one-third  of  the  superior  curved  line  of  the  occipital  b<> 
the  external  occipital  protuberance,  the  ligamentum  undue,  the  spinnus  proce-s 
of  the  seventh  cervical  vertebra  (vertebra  prominens),  the  spinous  processes  of  all 
the  thoracic  or  dorsal  vertebra',  and  from  the  intervening  snpra-spimms  ligaments. 
From  this  extensive  origin  its  fibers  converge  outward  to  the  top  of  the  shoulder. 
It  is  inserted  into  the  contiguous  margins  of  the  clavicle,  acromion  process,  and 
spine  of  the  scapula,  Vicing  attached  to  the  outer  one-third  of  the  posterior  border 
and  upper  surface  of  the  clavicle,  to  the  inner  border  of  the  upper  surface  of  the 
acromion  process,  and  to  the  entire  length  of  the  upper  margin  of  the  spine  of  the 
scapula.  The  lowermost  libers  form  a  triangular  aponeurosis  at  the  base  of  the 
spine  of  the  scapula,  over  which  it  glides  to  he  inserted  into  a  tubercle  at  the 
inner  extremity  of  the  spine.  Between  the  base  of  the  spine  of  the 'scapula  and 
the  tendon  is  a  small  synovial  bursa,  which  facilitates  the  movements  of  the 
tendon.  The  muscle  is  tendinous  at  its  attachments,  and  is  lusterless  and  adherent 
to  the  skin  in  the  occipital  region,  while  between  the  sixtli  cervical  and  third 
thoracic  spines  the  aponeurosis  of  origin  is  semi-elliptic,  forming  a  complete  ellipse 
with  its  fellow  of  the  opposite  side.  The  two  trapczii  form  a  diamond-shaped 
quadrangle, — a  trapezium  (hence  the  name), — with  the  lateral  angles  at  the 
shoulders  and  the  vertical  angles  at  the  occiput  and  twelfth  dorsal  spine. 

The  trape/.ius  muscle  is  subcutaneous  throughout  its  entire  extent  ;  in  the 
neck  it  rests  upon  the  complexus,  splenius  capitis  et  colli,  levator  anguli  scapula-, 
ami  rhomboideus  minor  muscles  ;  and  in  the  hack  upon  the  rhomboideus  major, 
supra-spinatus,  infra-spinatus,  part  of  the  serratus  posticus  superior,  latissimus 
dorsi  muscles,  and  the  vertebral  aponeurosis.  Its  anterior  cervical  border  forms 
the  posterior  boundary  of  the  posterior  common  triangle  of  the  neck,  and  is  nearly 
parallel  with  the  posterior  fibers  of  the  sterno-cleido-mastoid  muscle. 

BLOOD  SUPPLY. — From  the  princeps  cervicis,  superficial  cervical,  and  posterior 
scapular  arteries. 

NERVE  SUPPLY. — From  the  spinal  accessory  nerve  and  deep  branches  of  the 
cervical  plexus  which  enter  the  muscle  beneath  its  anterior  margin  near  the 
clavicle. 

ACTION. — The  upper  fibers  elevate  the  outer  end  of  the  clavicle  and  the  point 
of  the  shoulder;  acting  from  their  insertion  they  rotate  the  head,  draw  it  to  the 


PLATE  Gil. 


Splenius  capitis  m. 

Sterno-mas' 
Ltgamentum  nuchae 

Trap- 


Rhomboideus  major 
Latisslmus  dorsi 


External  oblique  rn 


Aponeurosis  of  latissimus  dorsi 


Internal  oblique  m. 
in  triangle  of  Petit 


Comp!e> 

Great  occipital  n. 
Splenius  capitis  m. 
.Serratus  posticus  supeiioris  m. 
Spltntus  cofli  rri , 
Levator  anguli  scapulae  m. 

Rhomboideus  minor  m. 
Serratus  magnus  m, 
Supraspinatus  m. 

Teres  minor  m. 


Outer  head  of 

triceps  m, 


Long  head  of 

triceps  m. 
Teres  major  m. 
nfraspinatus  m. 
Rhomboideus  major  m. 


Serratus  magnus  m. 
Vertebral  fascia 


Serratus  posticus  inferiors  m. 


External  oblique  m. 


Internal  oblique  m. 


MUSCLES  OF  BACK. 
373 


Tin-:  n.K'i\   <>/•'  Tin-:  M-:CK.  xii<>ru>rjL  AM>  Ti;r.\h'.  375 

same  side,  ami  extend  the  neck.  The  middle  fillers  draw  the  scapula  Inward  the 
spines  (if  the  vertebra',  and  rotate  il  so  as  to  raise  the  point  of  the  shoulder.  The 
lower  lihers  draw  Hie  shoulder  Made  inward  and  downward,  and  rotate  it  so  as  to 
elevate  the  point  of  the  shoulder.  Acting  as  a  whole,  the  two  muscles  draw  the 
seapuhe  nearer  together;  elevate  the  point  of  the  shoulder,  and  extend  the  neck, 
as  in  opisthotoiios. 

The  ligamentum  nuchee  is  a  fibro-elastic  band  extending  from  the  external 
occipital  protuberance  to  the  spine  of  the  seventh  cervical  vertebra,  where  it  is 
continuous  with  the  supra-spinous  ligaments  of  the  hack.  Fibrous  extensions 
from  it  to  the  underlying  spines  of  the  cervical  vertebra'  form  a  septum  between 
the  muscles  of  the  two  sides  of  the  back  of  the  neck.  It  is  almost  rudimentary  in 
man,  but  in  the  living  body  can  be  identified  through  the  skin  by  dropping  the 
head  forward  and  allowing  it  to  hang  by  its  own  weight,  when  the  ligament  can  be 
demonstrated.  In  the  lower  animals,  such  as  the  horse,  the  ligamentum  nuch;e 
holds  the  head  up  without  any  effort ;  in  fact,  muscular  force  is  required  to  carry 
the  head  to  the  ground  and  hold  it  there,  as  in  grazing. 

The  latissimus  dorsi  is  a  broad,  flat,  triangular  muscle,  with  an  elongated 
and  twisted  apex.  It  lies  upon  the  lower  portion  of  the  back  and  outer  side  of 
the  chest,  covering  a  part  of  the  side  of  the  latter  structure  and  all  of  the  back 
from  the  level  of  the  sixth  thoracic  vertebra  to  the  crest  of  the  ilium. 

This  muscle  arises  by  an  aponeurosis  from  the  spinous  processes  of  the  lower 
six  thoracic,  the  lumbar,  and  the  sacral  vertebra?,  the  intervening  supra-spinous 
ligaments,  the  back  of  the  sacrum,  and  the  posterior  one-third  of  the  outer  lip  of 
the  crest  of  the  ilium,  and  from  the  lower  three  or  four  ribs  by  fleshy  finger-like 
bands  which  interdigitate  with  similar  processes  of  the  external  oblique  muscle. 
Its  sacral  origin  is  in  common  with  that  of  the  erector  spime  muscle,  and  its 
aponeurosis  is  the  posterior  layer  of  the  lumbar  fascia.  Its  fibers  converge  to  the 
common  tendon.  The  upper  fibers  pass  horizontally  outward  over  the  inferior 
angle  of  the  scapula;  the  middle,  obliquely  upward  and  outward  ;  and  the  lower, 
almost  vertically  upward.  At  the  side  of  the  chest  they  form  a  long,  thick,  fleshy 
mass,  which  sometimes  receives  an  additional  slip  from  the  inferior  angle  of  the 
scapula  and  passes  along  the  axillary  border  of  that  hone  in  contact  with  the  teres 
major  muscle,  around  which  the  latissimus  dorsi  turns.  It  is  inserted  into  the 
bottom  of  the  bicipital  groove  between  the  insertions  of  the  teres  major  and 
pectoralis  major  muscles  by  a  flat  tendon  about  three  inches  long.  Near  its 
insertion  it  twists  upon  itself  so  that  the  lower  fibers  are  inserted  highest,  and  the 
upper  ones  lowest.  The  inferior  margin  of  the  tendon  is  united  to  that  of  the 
teres  major  muscle,  a  bursa  usually  existing  between  the  two.  Sometimes  there  is 
another  bursa  between  this  muscle  and  the  lower  angle  of  the  scapula.  As  it 


:;:<;  SURGICAL  ANATOMY. 

turns  around  the  terea  major  it  forms  with  that  muscle  the  posterior  told  of  the 
axilla. 

The  latissimus  dorsi  muscle  is  subcutaneous  throughout  its  entire  extent, 
exeent  at  thai  portion  of  its  origin  where  it  is  overlapped  by  the  trape/.ius  muscle. 
It  lies,  1'rom  below  upward,  upon  the  vertebral  aponeurosis  which  covers  the  erector 
spinse  muscle  and  its  upward  continuations,  the  serratus  posticus  inferior  muscle, 
lower  ribs,  external  intercostal  muscles,  serratus  magnus  muscle,  interior  angle  of 
the  scapula,  rhomboideus  major,  infra-spinatus,  and  teres  major  muscles.  Just 
above  the  crest,  of  the  ilium  there  appears,  except  in  very  muscular  subjects,  a 
triangular  interval  (trimii/Jr  <•>/  l'<fi/).  which  is  bounded  below  by  the  crest  of  the 
ilium,  behind  by  the  anterior  bonier  of  the  latissimus  dorsi  muscle,  and  in  front 
by  the  posterior  border  of  the  external  oblique  muscle.  Its  floor  is  formed  by  the 
internal  oblique  muscle.  This  triangle  is  not  present  in  very  muscular  subject-, 
because  the  posterior  border  of  the  external  oblique  muscle  is  overlapped  by  the 
latissimus  dorsi  muscle.  When  the  arm  is  abducted,  a  small  triangular  interval 
exists  between  the  upper  border  of  the  latissimus  dorsi  muscle,  the  vertebral  border 
of  the  scapula,  and  the  trapezius  muscle.  In  the  floor  of  this  triangle  are  found 
the  lower  part  of  the  rhomboideus  major  muscle  and  the  sixth  intercostal  space. 
With  the  exception  of  the  median  line  of  the  sternum,  this  is  the  only  part  of  the 
wall  of  the  thorax  which  is  not  covered  by  muscle. 

XKKVK  SUPPLY. — From  the  long  subscapular  nerve. 

BLOOD  SUPPLY.— From  the  subscapular  artery. 

ACTION. — It  is  an  internal  rotator  of  the  humerus  and  draws  the  arm  down- 
ward and  backward.  Acting  from  its  insertion  it  elevates  the  lower  ribs,  as  in 
forced  inspiration,  laterally  flexes  the  spinal  column,  and  draws  the  trunk  and 
pelvis  forward  and  upward,  and  hence  is  much  used  in  horizontal-bar  exercise 
and  climbing.  It  is  well  developed  in  swimmers,  as  it  draws  the  arm  downward 
and  at  the  same  time  rotates  it  inward. 

DISSKI TION. — The  trapezius  muscle  should  now  be  cut  through  about  one  and 
one-half  inches  from  its  vertebral  attachment  and  reflected  outward,  carrying  with 
it  the  deep  layer  of  the  deep  fascia  which  covers  the  under  surface  of  the  muscle. 
Dissection  of  the  deep  surface  of  the  trapczius  muscle  will  demonstrate  the  pres- 
ence of  the  spinal  accessory  nerve,  branches  of  the  cervical  plexus,  and  the  terminal 
portion  of  the  superficial  cervical  artery.  The  nerve  filaments  join  to  form  the 
siibtrapezial  plexus,  twigs  from  which  supply  the  muscle.  In  close  relation  with 
the  lower  portion  of  the  spinal  accessory  nerve  is  the  superficial  cervical  artery, 
which,  if  traced  downward  to  the  anterior  border  of  the  trapezius  muscle,  will  be 
seen  to  arise  from  the  transversalis  colli  artery. 

Reflection    of   the   trape/.ius    muscle   will    expose    a    group  of   three   muscles 


Till-:  HACK   or   Till-:  NECK,   SHOULDER,    A\f>    TRUNK.  377 

attached  to  the  posterior,  or  vertebral,  border  of  the  scapula  :  The  levalor  anguli 
scapula',  above  tlie  base  of  the  spine;  the  rhomhoideus  minor,  opposite  the 
base  of  the  spine:  and  the  rhomboideus  major,  below  the  base  of  the  spine. 
The  posterior  belly  of  the  omo-hyoid  muscle,  which  arises  from  the  upper  border 
of  the  seapula  internal  to  the  supra-scapular  notch,  will  also  be  seen. 

The  levator  anguli  scapulas  muscle  arises  from  the  posterior  tubercles  of  the 
transverse  processes  of  the  upper  four  cervical  vertebra'  by  lour  tendinous  slips. 
These  slips  unite  to  form  a  Hat,  fleshy  mass,  which  passes  down  the  back  of  the 
side  of  the  neck  to  be  inserted  into  the  vertebral  border  of  the  scapula  above  the 
base  of  the  spine.  Its  superficial  surface  is  in  relation  with  the  deep  fascia  of  the 
neck,  the  middle  scalene,  the  trapexius,  and  sterno-mastoid  muscles,  the  internal 
jugular  vein,  the  spinal  accessory  nerve,  and  some  of  the  descending  branches  of 
the  cervical  plexus.  It  rests  upon  the  spleiiius  colli,  transversalis  colli,  cervicalis 
ascendens,  and  serratus  posticus  superioris  muscles,  and  the  posterior  scapular 
vessels. 

BLOOD  SUPPLY. — From  the  vertebral,  ascending  cervical,  superficial  cervical, 
and  posterior  scapular  arteries. 

NERVE  SUPPLY. — From  the  fifth  cervical  nerve,  and  additional  filaments  from 
the  deep  branches  of  the  cervical  plexus. 

ACTION. — This  muscle  draws  the  upper  angle  of  the  scapula  upward  and 
forward,  at  the  same  time  rotating  that  bone  so  as  to  depress  the  summit  of  the 
shoulder.  Acting  from  its  insertion,  it  inclines  the  neck  to  one  side  and  extends  it. 

The  rhomboideus  minor  is  a  small,  fiat,  ribbon-like  muscle  arising  from  the 
lower  end  of  the  ligamentum  undue,  the  last  cervical  and  first  thoracic  spines,  and 
the  supra-spinous  ligament.  It  extends  obliquely  downward  and  outward,  and  is 
inserted  into  the  vertebral  border  of  the  scajmla  opposite  the  base  of  the  spine. 
It  is  covered  by  the  trapezius  muscle,  and  lies  upon  the  serratus  posticus  superioris 
and  intercostal  muscles,  the  posterior  scapular  artery,  and  the  ribs. 

BLOOD  SUPPLY. — From  the  posterior  scapular  artery. 

NERVE  SUPPLY. — From  a  branch  of  the  fifth  cervical  nerve  which  will  be 
seen  beneath  the  rhomboidei. 

ACTION. — It  draws  the  scapula  upward  and  inward  toward  the  spinal  column. 

The  rhomboideus  major  muscle  lies  below  the  rhomboideus  minor,  and  is 
about  three  times  as  broad.  It  arises  from  the  upper  four  or  five  thoracic  spines 
and  their  suj>ra-spinous  ligaments,  and  is  inserted  into  the  vertebral  border  of 
the  scapula  opposite  the  infra-spinous  fossa. 

This  muscle  and  the  rhomboideus  minor  have  similar  relations,  except  that 
the  former  covers  part  of  the  sj>lenius  colli,  the  vertebral  ajioneurosis,  and  the 
erector  spina?  muscle. 


378  SURGICAL    ANATOMY. 

BLOOD  SriM'LY. — From  the  posterior  scapular  artery. 

NERVE  SITI-LY. — From  a  branch  of  the  fifth  cervical  nerve. 

ACTION. — It  draws  the  scapula  upward  and  inward  toward  the  spinal  column, 
and  rotates  the  scapula  so  as  to  depress  the  summit  of  the  shoulder. 

DISSKCTION. — The  fatty  tissue  covering  the  posterior  belly  of  the  omo-hyoid 
muscle  should  lie  removed,  when  this  muscle  will  be  seen  to  arise  from  the 
superior  border  of  the  scapula  immediately  internal  to  the  supra-scapular  notch, 
and  in  part  from  the  ligament  converting  the  notch  into  a  foramen.  Jt  passes 
forward  and  upward  into  the  neck. 

Divide  the  posterior  belly  of  the  omo-hyoid  muscle  a  short  distance  above  its 
origin  and  reflect  it  upward.  This  will  expose  the  supra-scapular  artery  and  nerve 
on  their  way  to  enter  the  supra-scapular  fossa. 

Before  dividing  the  levator  anguli  scapuhe  and  rhomboidei  muscles  the 
dissector  should  turn  his  attention  to  the  cap  of  the  shoulder,  as  this  covers  many 
of  the  structures  to  be  considered. 

The  cap  of  the  shoulder  is  formed  by  the  deltoid  muscle,  which  is  covered  by 
a  part  of  the  dec))  fascia  called  the  deltoid  aponeurosis.  This  aponeurosis  is  thick 
and  strong,  and  sends  many  septa  between  the  bundles  of  fibers  of  the  muscle. 
The  fascia  is  continuous  with  that  covering  the  pectoralis  major  muscle  in  front 
and  the  infra-spinatus  muscle  behind,  and  is  attached  to  the  clavicle,  acromion, 
and  spine  of  the  scapula. 

The  deltoid  muscle  resembles  an  inverted  triangle  with  an  indented  base  ;  or 
the  (Jreek  J  inverted;  hence  its  name,  delta-like.  It  arises  from  the  shoulder 
girdle  opposite  the  insertion  of  the  trape/dus  muscle,  and  so  marked  is  this  that 
the  clavicle  and  acromion  process  and  spine  of  the  scapula  seem  but  bony  inter- 
ruptions in  one  grand  trapezo-dcltoid  muscle  which  is  inserted  into  the  middle  of 
the  humcrus.  It  arises  from  the  outer  one-third  of  the  anterior  border  of  the 
clavicle,  the  outer  border  and  superior  surface  of  the  acromion  process,  and 
the  entire  lower  border  of  the  spine  of  the  scapula.  From  these  points  its  fibers 
converge  to  form  a  thick,  short  tendon,  which  is  inserted  into  the  middle  of 
the  outer  side  of  the  shaft  of  the  humcrus  opposite  the  insertion  of  the  coraco- 
brachialis  muscle.  Its  fibers  are  irregular  in  direction,  presenting  a  twisted 
appearance,  and  coiling  behind  one  another.  There  are  several  main  bundles. 
Many  tendinous  intermuscular  septa  subdivide  it,  giving  insertion  to  some  of  its 
fibers  and  origin  to  others,  the  largest  bundle  coming  from  the  tip  of  the  acromion. 
On  account  of  these  tendinous  septa  the  deltoid  resembles  the  glutens  maximus 
muscle.  It  rounds  off  the  shoulder.  Superficially,  this  muscle  is  related  to  the 
platysma.  deep  fascia,  and  supra-acromial  nerves.  It  almost  completely  envelopes 
the  shoulder-joint,  and  is  separated  from  the  greater  tuberosity  of  the  humerus  by 


THE    HACK   or   THE  NECK,    SlfOfLDER,    AXI)    Th'l'XK.  379 

a  large  samilated  bursa.  It  covers  the  coracoid  process  of  the  scapula,  the  tendons 
of  the  pectorales  niajur  and  minor,  the  coraeo-hraehialis,  the  subscapularis,  the  short 
and  long  heads  of  the  biceps,  the  supra-spinatus,  the  infra-spinatus,  the  tores  minor, 
the  long  and  outer  heads  of  the  triceps,  the  coraco-clavicular  and  coraco-acromial 
ligaments,  the  circumilex  vessels  and  nei've,  and  the  upper  end  of  the  humerus. 
Anteriorly,  it  adjoins  the  upper,  outer  margin  of  the  pectoralis  major  muscle,  with 
which  it  forms  the  delto-pectoral  sulcus  in  which  is  lodged  the  cephalic  vein  and 
the  descending  hranch  of  the  acromio-thoracic  artery.  Abscess  of  the  shoulder- 
joint,  or  the  subdeltoid  hursa,  rarely  burrows  through  the  substance  of  this  muscle 
but  usually  points  at  one  of  its  borders. 

Atrophy  of  the  deltoid  muscle  causes  the  acromion  process  to  appear  more 
prominent,  and  a  depression  to  exist  beneath  it.  This  condition  is  caused  by 
disuse,  as  in  ankylosis  of  the  shoulder-joint ;  more  frequently  by  diseases  of  the 
spinal  cord,  as  acute  anterior  polio-myelitis  ;  by  ascending  neuritis  of  the  circum- 
flex nerve,  usually  due  to  disease  of  the  shoulder-joint  and  causing  paralysis  of 
the  muscles ;  and  by  injury  of  the  circumflex  nerve,  by  a  blow  or  fracture  of  the 
upper  part  of  the  humerus.  A  careless  observer  might  regard  a  case  of  atrophy 
of  the  deltoid  one  of  dislocation  of  the  head  of  the  humerus. 

BLOOD  SUPPLY. — From  the  acromio-thoracic,  the  anterior  and  posterior 
circumflex  arteries. 

NERVE  SUPPLY. — From  the  circumflex  nerve. 

ACTION. — It  is  by  no  means  simple  in  its  action.  The  whole  muscle  abducts 
the  arm,  raising  it  to  a  right  angle  with  the  body.  The  posterior  fibers  retroduct 
the  arm  and  rotate  it  outward  ;  and  the  anterior  fibers  draw  the  arm  forward  and 
rotate  it  inward.  Thus  this  muscle  draws  the  arm  forward,  backward,  or  outward, 
and  rotates  it  inward  or  outward. 

DISSECTION. — Divide  the  deltoid  muscle  about  one  inch  from  its  origin,  and 
reflect  it  downward.  This  will  expose  the  structures  already  enumerated  as  in 
relation  with  its  under  surface.  When  reflecting  the  muscle,  the  bursa  separating 
the  deltoid  muscle  from  the  acromion  process  and  the  greater  tuberosity  may  have 
been  opened  ;  but  if  it  be  still  intact,  it  should  be  incised  and  its  extent  carefully 
noted  by  passing  the  finger  into  it.  In  some  injuries  of  the  shoulder  this  bursa 
may  be  affected  by  traumatic  bursitis,  with  marked  increase  of  the  fluid  contents 
of  the  sac.  This  would  cause  much  prominence  of  the  shoulder  cap,  an'd  the 
consequent  increased  pressure  would  account  for  much  of  the  pain  experienced 
upon  movement  of  the  arm. 

Divide  the  latissimus  dorsi  muscle  just  above  the  level  of  the  inferior  angle 
of  the  scapula,  and  reflect  the  two  portions.  The  lower  portion  of  the  muscle 
should  not  be  reflected  beyond  its  aponeurosis. 


SURGICAL   A\'.\T<>MY. 

Circumflex  arteries  and  nerve. — The  anterior  and  posterior  circumflex 
arteries  and  the  ciivunilk'x  nerve,  which  \\-.\\c  been  described  \vitli  tlie  dissection 
of  the  axilla,  will  be  seen  on  the  under  surface  of  the  ivilecied  deltoid  muscle. 

The  teres  major  muscle  arises  IVoni  the  lower  part  of  the  axillary  border 
of  the  scapula,  from  the  back  of  the  inferior  angle  of  the  scapula,  and  from  the 
fibrous  septum  between  the  teres  major  and  the  teres  minor  muscle.  It  passes 
upward  and  outward,  and  forms  a  short,  flat  tendon,  which  is  inserted  into  the 
posterior  bicipital  ridge  of  the  humerus  behind  the  tendon  of  the  latissimus  dorsi 
muscle,  from  which  it  is  separated  by  a  bursa. 

BLOOD  SUPPLY. — From  the  suhscapular  and  posterior  circumflex  arteries. 

NERVE  SUPPLY. — From  the  lower  subscapular  nerve. 

ACTION. — It  assists  the  latissimus  dorsi  muscle  in  adducting  the  arm  and 
rotating  it  inward  ;  if  the  arm  be  fixed  upward  and  forward,  it  rotates  the  scapula 
by  drawing  the  lower  angle  forward  ;  and  if  the  scapula  also  be  fixed,  it  assists 
the  latissimus  dorsi  muscle  in  drawing  the  trunk  upward  and  forward,  as  in 
climbing. 

The  infra-spinous  fascia  is  a  dense  membrane  which  covers  the  infra- 
spiuatus  and  teres  minor  muscles.  It  is  attached  to  the  circumference  of  the 
infra-spinous  fossa,  and  gives  origin  to  some  of  the  fibers  of  the  muscles  which  it 
covers.  At  the  outer  border  of  the  deltoid  it  gives  off  a  process  which  passes  over 
that  muscle.  This  fascia  must  lie  removed  to  expose  the  underlying  muscles. 

The  teres  minor  muscle  hugs  the  axillary  border  of  the  scapula.  It  arises 
from  the  upper  two-thirds  of  the  dorsal  surface  of  this  margin.  There  is  an  aponeu- 
rotic  lamina  between  it  and  the  teres  major  muscle,  and  a  lamina  between  it  and 
the  infra-spinatus  muscle.  It  passes  upward  and  outward,  slightly  diverging  from 
the  teres  major  muscle,  and  is  inserted  into  the  lowermost  of  the  three  facets  upon 
the  greater  tuberosity  of  the  humerus  and  the  bone  just  below  it.  It  is  covered  by 
infra-spinous  fascia,  the  deltoid  muscle,  and  the  deep  fascia,  while  beneath  it  are  the 
scapula,  the  dorsalis  scapuhe  artery,  the  long  head  of  the  triceps  muscle,  the 
teres  major  and  the  subscapularis  muscle,  and  the  back  of  the  shoulder-joint.  Its 
upper  border  is  in  contact  with  the  infra-spinatus  muscle,  while  the  lower  border 
assists  in  forming  the  upper  boundary  of  the  subscapular  triangle. 

BLOOD  SUPPLY. — From  the  posterior  circumflex  and  dorsalis  scapula?  arteries. 

NERVE  SUPPLY. — From  the  circumflex  nerve. 

ACTION. — It  is  an  external  rotator  of  the  humerus,  adducts  it,  protects  the 
back  of  the  shoulder-joint,  and  aids  in  holding  the  head  of  the  humerus  in  place. 

The  long  head  of  the  triceps  muscle  is  seen  arising  from  the  axillary  border 
of  the  scapula  just  below  the  glenoid  fossa.  It  passes  downward  toward  the  back  of 
the  arm,  between  the  two  teres  muscles,  and  through  the  triangular  space  formed  by 


PLATE 


Teres  major  m. 


Branch  of  dorsalis  scapulae  a. 
Latissimus  dorsi  tendon 


Supraspinatus  m. 


Infraspinatus  m. 


Greater  tuberoslty  of  humerus 
Teres  minor  m. 


Circumflex  n. 


Posterior  circumflex  a. 


Long  head  of  triceps  m. 


Outer  head  of  triceps  m. 


Ulnar  n.- 


Flexor  carpi  ulnaris  m- 


-Tendon  of  triceps  m. 


POST-SCAPULAR  MUSCLES  AND  TRICEPS  MUSCLE. 
381 


Till-:   BACK    OF   Till-    NECK,    sllon.DKi;.    A.\f>    VV.T.VA'.  383 

their  divergence  (the  teres  minor  being  behind   ami   the  teres   major  in  front),  sub- 
dividing tliis  interval    into  an   inner  triangular  and  an  outer   rectangular  space. 

(See     nisseetion     of     Axilla.)        TllO    former    gives     passage     lo     llie    dorsalis    scapulie 

Vessels,  and    (In-   latter  to  the  posterior  cireinnllex  vessels  and  the  eireunillex  nerve. 

The  scapula  lias  two  dorsal  fosse,  separated  by  the  spine  of  the  bone,  and  one 
anterior,  or  ventral,  making  tbree  in  all.  from  each  of  \vliich  arises  a  muscle; 
these  muscles  are  known  as  the  supra-spinalus,  infra-spinalus,  and  snbseapularis. 

The  infra-spinatus  muscle,  thick  and  triangular,  arises  from'  the  inner  two- 
thirds  of  the  infra-spinous  fossa,  the  under  surface  of  the  spine  of  the  scapula,  the 
infra-spinous  fascia,  and  the  septum  separating  it  from  the  teres  major  and  teres 
minor  muscles.  Its  fibers  converge  to  a  tendon  which  passes  below  the  concave 
outer  border  of  the  spine  of  the  scapula,  and  crosses  the, shoulder-joint  to  be  inserted 
into  the  middle  facet  upon  the  greater  tuberosity  of  the  hnmerus.  A  hursa,  which 
sometimes  communicates  with  the  shoulder-joint,  occasionally  exists  between  the 
tendon  and  the  outer  border  of  the  spine  of  the  scapula.  This  muscle  is  covered 
by  the  infrorepinous  J'uxrin,  which  sends  fibrous  septa  between  it  and  the  two  teres 
muscles,  and  is  continuous  with  the  deep  fascia  of  the  arm.  It  is  also  covered  by 
the  deltoid,  trape/ius,  and  latissimns  dorsi  muscles.  Beneath  it  lie  the  scapula, 
the  supra-scapular  vessels  and  nerve,  the  dorsalis  scapula-  vessels,  and  the  capsule 
of  the  shoulder-joint.  External  to  it  are  the  teres  major  and  teres  minor  muscles. 

BLOOD  Sri-i'LY. — From  the  dorsalis  .scapula?  and  supra-scapular  arteries. 

NERVE  SUPPLY. — From  the  supra-scapular  nerve. 

ACTION*. — It  rotates  the  humerus  outward,  adducts  it,  and  aids  in  holding  the 
head  of  the  bone  in  place. 

DISSECTION. — The  acromial  end  of  the  clavicle  and  the  acromion  process 
should  be  removed  so  as  to  fully  expose  the  top  of  the  shoulder-joint,  and  afford  a 
clearer  view  of  the  muscles  inserted  into  the  greater  tuberosity  of  the  humerus. 

The  supra-spinous  fascia  is  a  dense  membrane  covering  tin-  supra-spinatus 
muscle,  and  giving  origin  to  some  of  its  fibers.  It  is  very  thick  internally  but 
less  so  under  the  coraco-acromial  ligament.  It  is  attached  to  the  margins  of 
the  supra-spinous  fossa,  and  must  be  removed  to  expose  the  supra-spinatus  muscle. 

The  supra-spinatus  muscle  fills  the  supra-spinous  fossa,  and  arises  from  its 
inner  two-thirds,  the  upper  surface  of  the  spine  of  the  scapula,  and  the  fascia 
covering  the  muscle.  Its  fibers  converge  into  a  short,  stubby  tendon  which  crosses 
the  top  of  the  shoulder-joint  under  the  acromion  process,  to  be  attached  to  the 
uppermost  of  the  three  facets  upon  the  greater  tuberosity  of  the  humerus.  It  is 
closely  adherent  to  the  capsule  of  the  shoulder-joint.  Superficial  to  it  arc  the 
thick  and  dense  supra-spinous  aponeurosis,  the  trapezius  muscle,  clavicle,  acromion, 
coraco-acromial  ligament,  and  deltoid  muscle  ;  under  it  are  the  capsule  of  the 


::si  SURGICAL   ANATOMY. 

shoulder-joint,  the  supra -scapular  vessels  and  nerve,  the  oino-liyoid  muscle,  and  the 
scapula. 

IJi.ooi >  SriTLY. — From  the  supra-seapular  artery. 

NKUVK  Sci'iM.v. —  From    the  supra-scapular  nerve. 

ACTION. — ii  assists  the  dehoid  muscle  in  abducting  the  arm,  and  holds  the 
head  of  the  Immerus  in  contact  with  the  glcnoid  fossa. 

DISSK.CTIO.X. — Having  carefully  studied  the  muscles  just  descrihed,  the 
dissector,  in  order  to  ohtain  a  better  view  of  the  vessels  and  nerve  which  puss 
beneath  them,  should  divide  the  levutor  anguli  scapuhe  muscle  near  its  attachment 
to  the  base  of  the  scapula  and  relied  it  upward;  the  infra-spinatus  und  supra- 
spinatus  muscles  should  be  divided  near  their  insertions  and  reflected  inward  ; 
divide  the  rhomboidei  muscles  near  their  insertion  and  reflect  them  outward; 
then  divide  the  teres  minor  muscle  near  its  insertion  and  reflect  it  downward. 

The  posterior  scapular  artery,  one  of  the  terminal  branches  of  the  trans- 
versal is  colli.  runs  beneath  the  vertebral  border  of  the  scapula,  between  (lie  levator 
anguli  scapuhe  and  the  rhomboidei  muscles  behind  and  the  serratus  magnus 
muscle  in  front,  to  the  inferior  angle  of  that  bone,  where  it  anastomoses  with  the 
terminal  portion  of  the  subscapular  artery.  In  its  course  it  gives  oft'  numerous 
branches,  which  ramify  on  the  dorsal  and  ventral  aspects  of  the  scapula.  These 
branches  supply  the  rhomboidei,  supra-spinatus,  infra-spinatus,  trape/.ins,  and 
latissimus  dorsi  muscles.  They  anastomose  with  the  supra-scapular,  dorsal  is 
scapuhe,  subscapular,  and  branches  of  the  intercostal  arteries.  The  posterior 
scapular  often  arises  from  the  third  portion  of  the  subclavian  artery.  The  nerve 
to  the  rhomboidei  muscles  accompanies  this  artery. 

The  supra-scapular  artery,  a  branch  of  the  thyroid  axis,  after  passing  along 
the  under  surface  of  the  posterior  belly  of  the  oino-hyoid  muscle  enters  the-  supra- 
spinoiis  fossa  by  passing  over  the  transverse  ligament.  It  traverses  that  fossa 
beneath  the  supra-spinatus  muscle  and  passes  around  the  outer  border  of  the  spine 
of  the  scapula  and  enters  the  infra-spinous  fossa.  Within  these  foss;e  it  supplies 
the  supra-spinatus  and  infra-spinatus  muscles,  and  anastomoses  with  the  posterior 
scapular  and  dorsal  is  scapuhe  arteries. 

The  supra-scapular  nerve  accompanies  the  supra-scapular  artery,  but  passes 
through  the  supra-scapular  notch  beneath,  and  not  over,  the  transverse  ligament. 
It  supplies  twigs  to  the  supra-spinatus  muscle  and  the  shoulder-joint,  and  passes 
into  the  infra-spinous  fossa  together  with  the  supra-scapular  artery,  terminating  in 
the  infra-spinatus  muscle. 

The  dorsalis  scapulae,  a  branch  of  the  subscapular  artery,  enters  the  infra- 
spinous  fossa  by  winding  around  the  axillary  border  of  the  scapula  under  the 
teres  minor  muscle.  It  supplies  the  infra-spinatus  muscle  and  anastomoses  with 


PLATE  CIV, 


Branch  of 
Acromio-thoracic  a. 


Suprascapular  a. 


Branch  of 

posterior  circumflex  a1. 


Subscapular  a. 


Suprascapular  a 


Posterior  scapular  a. 


Dorsalis  scapulae  a.- 


25 


ANASTOMOSES  OF  ARTERIES  AROUND  THE  SCAPULA. 
385 


THE   HACK   OF   THE  .VAY'A",    SII»riJ)KK,    A.\J>    TRL'XK.  ;jx7 

thu  supra-scapular  and  posterior  scapular  arteries.  It  sends  a  branch  along  the 
axillarv  border  of  the  scapula,  between  the  teres  major  and  minor  muscles,  to  the 
posterior  surface  of  the  inferior  angle  of  that  bone,  where  it  again  anastomoses 
with  the  posterior  scapular  artery. 

The  subscapularis,  a  large  and  triangular  muscle,  fills  the  subscapular  fossa. 
It  arises  from  the  inner  two-thirds  of  that  fossa,  except  from  the  front  of  the  upper 
and  lower  angles  and  the  front  of  the  posterior  border  to  which  the  serratus  magnus 
muscle  is  attached.  Its  scapular  origin  is  fleshy,  except  at  the  ridges  on  the  bone, 
where  it  is  tendinous.  Its  filters  converge1  to  a  strong  tendon,  which  lies  below  the 
base  of  the  coracoid  process,  and  is  inserted  into  the  lesser  tuberosity  of  the 
humerus  ;  those  libers  arising  from  the  axillary  border  are  inserted  into  the  sur- 
gical neck  of  the  humerus  for  an  inch  below  the  lesser  tuberosity.  Between  its 
tendon  and  the  coracoid  process  is  found  a  large  bursa,  which  communicates  with 
the  shoulder-joint.  The  muscle  is  covered  by  a  thin  subscapular  aponeurosis 
attached  to  the  entire  circumference  of  the  fossa,  and  gives  origin  to  some  of  its 
fibers.  In  addition  to  this  covering  it  lies  behind  the  serratus  magnus  and 
coraco-brachialis  muscles,  the  short  head  of  the  biceps,  the  axillary  vessels  and 
brachial  plexus,  and  some  of  their  branches.  Behind,  it  rests  upon  the  scapula, 
the  teres  minor  muscle,  the  long  head  of  the  triceps,  the  capsule  of  the  shoulder- 
joint.,  and  the  intervening  bursa.  To  its  outer  side  are  the  teres  major  and  the 
latissimus  dorsi  muscle,  the  posterior  circumflex  and  dorsalis  scapulas  vessels, 
and  the  circumflex  nerve. 

BLOOD  SUPPLY. — From  the  axillary  and  subscapular  arteries. 

NERVE  SUPPLY. — From  the  short  and  lower  subscapular  nerves. 

ACTION. — It  is  an  internal  rotator  of  the  humerus,  draws  the  arm  downward 
after  it  has  been  raised,  and  holds  the  head  of  the  humerus  in  place. 

DISSI-XTIOX. — The  anterior  dissection  of  the  chest  having  been  made,  the 
clavicle  should  be  severed,  when  the  serratus  magnus  muscle  will  be  the  only 
remaining  connection  between  the  trunk  and  upper  extremity. 

The  serratus  magnus  muscle  is  closely  attached  to  the  upper  outer  anterior 
part  of  the  thorax.  It  arises  by  nine  fleshy  (limitations  from  the  upper  eight  ribs 
and  the  corresponding  interspaces,  two  digitations  arising  from  the  second  rib. 
From  this  broad  origin  its  fibers  converge  backward  around  the  chest  for  insertion 
into  the  anterior  surface  of  the  vertebral  border,  and  of  the  upper  and  low^er  angles 
of  the  scapula.  It  is  therefore  irregularly  quadrilateral  in  form.  It  is  con- 
veniently divided  for  examination  into  an  upper,  middle,  and  lower  part.  The 
vpper  .portion — narrowest,  thickest,  a,nd  shortest — consists  of  the  first  two  digita- 
tions arising  from  the  first  and  second  ribs  and  intervening  intercostal  space, 
whence  it  passes  upward,  outward,  and  backward  to  the  anterior  surface  of  the 


388  SURGICAL    ANATOMY. 

superior  angle  of  the  scapula.  The  ////</<//<  //«;•//«,/  consists  of  the  third,  fourth, 
til'tli  digitations  arising  from  the  second,  thinl,  and  fourth  rihs  and  intervening 
intercostal  spaces.  It  is  a  thinner  and  wider  layer  than  the  preceding  portion, 
and  passes  hori/.oiital  ly  backward  to  lie  inserted  into  the  anterior  surface  of  the 
vertebral  border  of  the  scapula  between  the  upper  and  lower  angles.  Th,.  lower 
l>i>,ii'in  consists  of  the  remaining  four  digitations  arising  from  tlie  fifth,  sixth, 
seventh,  and  eighth  rihs  and  the  corresponding  intervals,  and  interdigitates 
with  the  upper  serrations  of  the  external  oblique  muscle.  Its  fibers  pass  upward, 
outward,  and  backward,  to  be  inserted  into  the  oval  space  on  the  anterior  surface 
of  the  inferior  angle  of  the  scapula.  The  serratus  magnus  muscle  is  in  relation 
superficially  with  the  pectoralis  major  and  minor  muscles,  the  Bubscapularis  and 
latissimus  dorsi  muscles,  the  subclavian  and  axillary  vessels,  the  axillary  or 
brachial  plexus  of  nerves,  and  the  posterior  or  long  thoracic  nerve.  It  covers 
the  ribs,  intercostal  muscles,  and  serratus  posticus  superioris  muscle. 

BLOOD  SUPPLY. — From  the  axillary  and  intercostal  arteries. 

NERVK  Srppi.v. — From  the  posterior  or  long  thoracic  nerve  (external 
respiratory  of  Bell).  This  nerve  is  seen  running  over  the  muscle  at  the  side  of 
the  chest. 

ACTION. — It  draws  the  scapula  and  entire  shoulder  forward,  thus  increasing 
the  forward  reach  of  the  arm  and  antagonizing  the  rhomboidei  muscles  and  central 
fibers  of  the  trape/ius  muscle.  If  the  scapula-  are  fixed  close  to  the  spinal  column, 
tin1  lower  fibers  of  the  two  serratus  niagnus  muscles  will  evert  and  draw  the  ribs 
upward,  thus  pushing  the  sternum  outward  and  increasing  the  antero-posterior  and 
lateral  diameters  of  the  chest.  It  helps  sustain  weight  upon  the  shoulder  by 
holding  the  lower  angle  of  the  scapula  forward,  thus  aiding  the  trapezius  in 
drawing  the  summit  of  the  shoulder  upward.  It  holds  the  scapula?  firmly  against 
the  chest  wall,  and  its  lower  portion — by  far  the  strongest — pulls  the  inferior  angle 
of  the  scapula  forward.  It  steadies  the  scapula  while  the  deltoid  muscle  abducts 
the  arm  to  a  right  angle  ;  then,  by  rotating  the  inferior  angle  forward,  it  can  raise 
the  arm  to  the  vertical  position.  Paralysis  of  the  serratus  magnus  muscle  prevents 
the  deltoid  muscle  from  raising  the  arm,  and  allows  the  inferior  angle  and  verte- 
bral border  of  the  scapula  to  project  from  the  chest,  producing  the  "  winged 
scapula." 

Before  leaving  the  shoulder  the  student  should  carefully  note  the  actions  and 
relations  of  the  magnificent  tripartite  muscle  composed  of  the  trapezius,  deltoid, 
and  pectoralis  major  muscles.  The  trapezius  and  deltoid  may  be  considered,  for 
many  reasons,  a  single  muscle  ;  so  may  the  pectoralis  major  and  deltoid  muscles  be 
viewed  as  one  muscular  mass,  arising  from  an  extensive  origin,  beginning  at  the 
costo-chondral  margin  and  extending  up  the  side  of  the  sternum  and  along  the 


PLATE  GV. 


Long  head  of  b: 


Subscapularis  m. 


Teres  major  m. 
Long  head  of  triceps  m. 
Latissimus  dorsi  tendon 
Outer  head  of  triceps  m. 
ectoralis  major  tendon 
Inner  head  of  triceps  m. 


SUBSCAPULARIS  MUSCLE  AND  SUBSCAPULAR  TRIANGLE, 
390 


PLATE  CVI. 


External  intercostal  m. 
Internal  interco: ' 


Serratus  magnus  m. 


SERRATUS  MAGNUS  MUSCLE. 
391 


Tin-:  n.\<-K  or  '/•///•;  M-CK. 


AM>  n;r.\K. 


393 


entire  length  of  the  shoulder  girdle — /'.  e.,  tlie  clavicle,  acromion,  and  spine  of  the 
>ca|iula.  It  is  inserted  into  the  anterior  bicipital  ridge  and  the  middle  of  the 
outer  side  of  the  shaft  of  the  humcrns. 

The  following  grouping  of  the  seventeen  mnselcs  attached  to  the  scapula  will 
be  of  considerable  aid  to  the  student  in  remembering  them  : 


Three  to  the  vertebral  border, 


Three  to  the  axillary  border, 


Three  to  the  three  fossa;, 


Three  to  the  coracoid  process,  . 

Three  irregularly  attached,    .    . 
Two  to  the  spine  of  the  scapula, 


Serratus  magnus  muscle. 
Hliomboideus  minor  muscle. 
Rhomboideus  major  muscle. 

Long  head  of  triceps  muscle. 
Teres  minor  muscle. 
Teres  major  muscle. 

Supra-spinatus  muscle. 
Infra-spinatus  muscle. 
Subscapularis  muscle. 

Short  head  of  biceps  muscle. 
( '( iraco-braebialis  muscle. 
1'ectoralis  minor  muscle. 

Omo-hyoid  muscle. 

Long  head  of  the  biceps  muscle. 
Levator  anguli  scapulae  muscle. 

J  Trapezius  muscle. 
I  Deltoid  muscle. 


DISSECTION. — It  is  now  necessary  to  remove  the  arm  and  scapula.  This  can 
be  done  by  dividing  the  coraco-clavicular  ligament,  the  serratus  magnus  muscle  at 
its  origin,  and  the  axillary  vessels  and  brachial  plexus  of  nerves. 

There  are  two  serratus  posticus  muscles — the  superior  and  inferior.  The 
superior  lies  under  the  three  muscles  attached  to  the  vertebral  border  of  the 
scapula  ;  and  the  inferior  under  the  latissimus  dorsi  muscle. 

The  serratus  posticus  superioris  is  a  thin,  flat  muscle,  which  arises  by  a  thin 
aponeurosis  from  the  lower  end  of  the  ligamentum  nucha?,  the  last  cervical  and 
the  upper  two  or  three  thoracic  spines;  it  is  inserted  by  four  fleshy  slips  into  the 
upper  borders  of  the  second,  third,  fourth,  and  fifth  ribs  beyond  their  angles.  The 
fibers  are  directed  downward  and  outward.  It  is  covered  by  the  trapezius  and  the 
levator  anguli  scapulae  and  the  rhomboidei  muscles.  It  lies  upon  the  splenius 
muscle,  the  vertebral  aponeurosis  covering  the  upper  continuations  of  the  erector 
spime,  upon  the  intercostal  muscles,  and  the  ribs. 

NERVE  SUPPLY. — From  the  branches  of  the  second  and  third  intercostal 
nerves. 


SURGICAL   ANATOMY. 

ACTION. — It  draws  upward  the  ribs  to  which  it  is  attached,  assisting  in 
inspiration. 

The  serratus  posticus  inferioris  is  also  a  thin.  Hat  muscle.  It  arises  by  an 
aponeurosis  from  the  last  two  dorsal  and  upper  two  or  three  hmihar  spines  and 
from  the  interspinous  ligaments.  It  passes  upward  and  outward,  and  is  inserted 
by  four  fleshy  (limitations  into  the  lower  borders  of  the  lower  four  ribs  beyond  their 
angles.  It  is  covered  hy  (lie  latissimus  dorsi  muscle  and  rests  n|>on  the  erector 
spina-  and  its  continuations,  upon  the  levatores  costaruin  and  intercostal  muscles, 
and  rihs.  Its  upper  margin  blends  with  the  vertebral  aponeurosis. 

'NiOKVK  Sri'iM.Y. — -From  the  branches  of  the  tenth  and  eleventh  intercostal 
nerves. 

ACTION. — It  depresses  and  fixes  the  lower  four  ribs,  resisting  the  action  of  the 
diaphragm,  which  tends  to  elevate  and  draw  forward  the  lower  ribs;  it  is  a  muscle 
of  inspiration. 

The  splenius  muscle  (spleuius  capitis  et  colli)  arises  from  the  lower  two- 
thirds  of  the  ligaineiitum  nuchie,  and,  hy  tendinous  slips,  from  the  spines  of  the 
last  cervical  and  upper  six  thoracic  vertebra',  and  the  intervening  interspinous  liga- 
ments. It  passes  upward  and  outward,  expanding  into  a  broad,  flat  muscle  which 
divides  into  two  portions,  one  going  to  the  head  and  the  other  to  the  neck.  The 
head  segment  (splenius  capitis)  is  inserted  into  the  mastoid  process  of  the  temporal 
bone  and  the  surface  of  the  occipital  hone  helow  the  superior  curved  line  and 
under  the  sterno-cleido-mastoid  muscle.  The  neck  segment  (splenius  colli)  is 
inserted  into  the  posterior  tubercles  of  the  transverse  processes  of  the  upper  three 
or  four  cervical  vertebra1.  The  muscle  is  covered  by  the  posterior  process  of  the 
deep  cervical  fascia  and  the  following  muscles:  Trape/ius,  serratus  posticus  siipe- 
rioris,  rhomboidei,  levator  anguli  scapuhe,  sterno-cleido-mastoid.  It  lies  upon  the 
spinalis  dorsi,  semi-spiualis  colli,  longissimus  dorsi,  cervicalis  ascendeiis,  trans- 
versalis  colli,  complexus,  and  trachelo-mastoid  muscles. 

NEKVK  .SrrrLY. — From  the  external  branches  of  the  posterior  divisions  of 
the  lower  cervical  nerves. 

ACTION. — It  extends  the  head  and  neck,  rotates  them  to  the  same  side,  and 
flexes  them  laterally. 

The  vertebral  fascia  or  vertebral  aponeurosis  is  a  thin,  fibrous  membrane, 
which  extends  from  the  spines  of  the  vertebra'  to  the  angles  of  the  ribs,  and  binds 
down  the  muscles  occupying  the  vertebral  groove.  It  is  continuous  below  with 
the  upper  margin  of  the  serratus  posticus  inferioris  muscle  and  the  aponeurosis  of 
the  latissimus  dorsi  muscle;  above,  it  passes  under  the  serratus  posticus  superioris 
muscle  and  is  continuous  with  the  deep  fascia  over  the  spleuius  muscle.  This 
aponeurosis  separates  the  deeper  muscles  of  the  back  from  the  posterior  axo- 


PLATE  CVII, 


Complexus  m. 
Ligamentum  nuchae 

Splenius  capitis  m.- 

Splenius  colli  m, 

Scalenus  posticus  m 

Serratus  posticus  superioris  m. 
Supraspinous  lig. 


Vertebral  fascia 


Serratus  posticus 
inferioris  m.- 


Appneurosis  of 
latissimus  dorsi  m 

External  oblique  m 


Internal  oblique  m 


Obliquus  capitis  superioris  m. 
Complexus  m. 

Tracrtelo-mastoid  m. 


Transversalis  coMi  m. 
Semispinalis  colli  m. 
.Cervicalis  ascendens  m. 


Semispinalis  dorsi  m. 
Accessorius  ad  ilio-costalem  m, 
Spinalis  dorsi  m. 

Longissimus  dorsi  m. 
Ilio-costalis  m. 


Erector  spinaem. 


Lumbar  fascia 

.Cut  edge  of  posterior 
lamella  of  lumbar  fascia 

External  oblique  m. 
Internal  oblique  m. 


MUSCLES  OF  BACK, 
396 


PLATE  CVII  I. 


C  o  in  p  I  e  x  u  s  m  -. — 
Trachelo-mastoid  m 

Semispinalis  colli  m 
Transversalis  colli  m. 

Cervicalis  ascendens  in. 
Semispinalis  dorsi  m.— 

Longissimus  dorsi  m. 

Spinalis  dorsi  m  .- 
Accessorius  ad  ilio- costalem  m_ 


Ilio-costalis  m. 


Rectus  capitis  posticus  minor  m. 
Rectus  capitis  posticus  maior  m. 
Obliquus  capitus  superiorly  m. 

Obliquus  capitis  inferioris  m. 


Levatores  costarum 


Multifidus  spinaem. 


Middle  lamella  of 

lumbar  fascia 
Lumbar  fascia 


edge  of  posterior 
lamella  of  lumbar  fascia 

Transverse  process 


DEEP  MUSCLES  OF  BACK, 
397 


Till:   HACK    OF   Till-:   .V/-.VA',    S7/OT l.DT.R.    AND    TRUNK. 

appendicular  muscles — /.  e.,  those  muscles  upon  tin-  l>ark  which   unite  the  trunk 
with  the  upper  liml>. 

DISSKCTION. — Beginning  from  helow,  remove  the  aponeiirosis  of  tlie  latissimus 
dorsi  muscle,  the  serratns  posticus  inferioris  muscle,  and  the  vertebral  fascia. 
Pivi'le  tlie  Berratus  posticus  superioris  and  splcnius  muscles  at  their  middle,  and 
reflect  the  two  halves.  This  exposes  tin-  erector  spina-  muscle  and  its  upward 
continuations  and  the  greater  part  of  the  complexus  muscle. 

The  erector  spinae  is  an  extensive,  seetional  lihro-muscular  mass  with  uumer- 
uus  costo-vertebral  attachments  extending  the  entire  length  of  tlie  spine.  It  is 
densely  lihrons  and  poiuteil  in  the  sacral  region,  becomes  very  muscular  in  the 
lumbar  region,  and  divides  in  the  lower  dorsal  region  into  three  main  sections — an 
outer,  ilio-costalis  or  sacro-lumbalis  ;  an  inner,  spinalis,  dorsi  ;  and  an  intermediate, 
longissimus  dorsi.  It  arises,  by  a  thick  aponetirosis,  from  tlie  spines  of  the  lower 
two  thoracic,  from  the  lumbar,  and  upper  four  sacral  vertebra1;  from  the  back  of 
the  sacrum  and  the  posterior  sacro-iliac  ligaments;  and,  by  muscular  tib(>rs,  from 
the  posterior  fifth  of  the  crest  of  the  ilium.  The  whole  mass  ascends,  and  divides 
below  the  last  rib  into  three  column?-. 

The  outer  column  is  subdivided  into  the  ilio-costalis  or  sacro-lumbalis  and 
its  continuations — the  accessorius  ad  ilio-costalem  and  the  cervicalis  ascendens 
muscle. 

BLOOD  SUPPLY. — From  the  posterior  scapular,  intercostal,  and  lumbar  arteries. 

NERVE  SUPPLY. — From  the  external  branches  of  the  posterior  divisions  of  the 
spinal  nerves  in  the  lumbar,  thoracic,  and  cervical  regions. 

The  ilio-costalis  or  sacro-lumbalis  is  the  outermost  and  fleshy  part  of  the 
erector  spinae  muscle,  and  is  inserted  into  the  angles  of  the  ribs  from  the  sixth  to 
the  eleventh,  and  into  the  inferior  border  of  the  twelfth,  the  transverse  processes  of 
the  lumbar  vertebra,  and  into  the  middle  layer  of  the  lumbar  fascia.  Very  often 
this  muscle  is  inserted  as  high  as  the  fourth  rib. 

NERVE  SUPPLY. —  From  the  external  branches  of  the  posterior  divisions  of  the 
spinal  nerves  in  the  lumbar  and  thoracic  regions. 

ACTION. — It  depresses  the  ribs,  and  is,  therefore,  a  muscle  of  expiration.  It 
keeps  the  body  erect  by  extending  the  spinal  column,  which  it  also  flexes  laterally. 

DISSECTION. — Turn  the  ilio-costalis  muscle  outward  to  expose  the  origins  of 
the  accessorius  muscle. 

The  accessorius  muscle  (accessorius  ad  ilio-costalem)  is  the  upward  continua- 
tion of  the  ilio-costalis  muscle  and  arises,  by  tendinous  slips,  from  the  angles  of 
the  lower  six  ribs,  internal  to  the  costal  insertions  of  the  ilio-costalis  muscle.  It  is 
inserted  into  the  angles  of  the  upper  six  ribs  and  the  transverse  process  of  the 
seventh  cervicalfvertebra. 


it  HI  SURGICAL    AXATOMY. 

XKRVE  SUPPLY. — From  the  external  branches  of  the  posterior  divisions  of  the 
spinal  nerves  in  the  thoracic  region. 

ACTION. — With  fixation  of  the  lower  six  ribs  hy  the  ilio-costalis  this  muscle 
draws  downward  the  upper  six  rihs,  as  in  expiration.  It  also  aids  in  extension 
and  lateral  flexion  of  the  spinal  column  ;  acting  from  its  insertion,  it  elevates  the 
lower  six  ribs,  as  in  inspiration. 

The  cervicalis  ascendens  is  the  continuation  of  the  am-ssorius  muscle  and 
arises  from  the  upper  four  or  five  rihs  internal  to  the  costal  insertions  of  the  acces- 
sorius  muscle.  It  passes  upward  over  the  first  rib  and  the  Iransversalis  colli 
muscle,  and  is  inserted  into  the  posterior  tubercles  of  the  transverse  processes  of 
the  fourth,  fifth,  and  sixth  cervical  vertebrae. 

XKKVK  SUPPLY. — From  the  external  branches  of  the  posterior  divisions  of  the 
spinal  nerves  in  the  thoracic  and  cervical  regions. 

ACTION. — It  extends  the  neck  and  flexes  it  laterally.  Acting  from  its  inser- 
tion, it  elevates  the  ribs  to  which  it  is  attached,  as  in  inspiration. 

The  intermediate  column  consists  of  the  longissimus  dorsi,  transversalis  colli, 
and  trachelo-mastoid  muscles. 

BLOOD  SUPPLY. — From  the  princeps  cervicis,  proftmda  cervicis,  intercostal,  and 
lumbar  arteries. 

The  longissimus  dorsi  muscle  is  the  largest  of  the  erector  spinse  group.  Its 
inner  side  lies  in  close  contact,  in  the  lumbar  region,  with  the  spinalis  dorsi 
muscle,  from  which  it  often  receives  a  slip.  It  has  two  series  of  insertions — an 
inner,  or  vertebral ;  and  an  outer,  or  costal :  the  inner  series,  by  rounded  tendons, 
is  attached  to  the  transverse  processes  of  all  of  the  thoracic  and  the  lumbar 
vertebra? ;  the  outer  series,  by  fleshy  and  tendinous  slips,  is  inserted  into  all  of  the 
ribs  external  to  the  tubercles,  the  transverse  processes  of  the  lumbar  vertebra-,  and 
the  adjacent  portion  of  the  middle  lamella  of  the  lumbar  fascia. 

XKRVE  SUPPLY. — From  the  external  branches  of  the  posterior  divisions  of  the 
spinal  nerves  in  the  lumbar  and  thoracic  regions. 

ACTION. — It  extends  the  spinal  column,  flexes  it  laterally,  and  depresses  the 
ribs,  as  in  expiration. 

The  transversalis  colli  muscle  is  the  upward  continuation  of  the  longissimus 
dorsi,  and  is  situated  upon  the  inner  side  of  that  muscle.  It  arises  from  the  trans- 
verse processes  of  the  upper  five  or  six  thoracic  vertebrae,  and  is  inserted  into  the 
posterior  tubercles  of  the  transverse  processes  of  the  cervical  vertebras  from  the 
second  to  the  sixth. 

NERVE  SUPPLY. — From  the  external  branches  of  the  posterior  divisions  of  the 
spinal  nerves  in  the  thoracic  and  cervical  regions. 

ACTION. — It  extends  the  neck,  flexes  it  laterally,  and  rotates  it  to  the  same  side. 


mi:  HACK  or  THE  .Y/-.V-A-.  Miori.nr.n.  A.\D  TRUNK.  401 

The  trachelo-mastoid  muscle  is  .-iuiated  upon  the  inner  side  of  the  trans- 
versalis  rolli.  and  forms  the  continuation  of  that  muscle  toward  (lie  head.  It 
arises  from  the  transverse  processes  (»f  the  third,  fourth,  fifth,  and  sixtli  thoracic 
vertebra*  and,  hy  additional  tendons,  from  tin-  hack  of  the  articular  processes  of 
the  lower  three  or  four  cervical  vertebra'.  It  proceeds  upward  as  a  small  muscle 
which  is  inserted  into  the  posterior  border  of  the  mastoid  process  under  the  splenius 
and  sterno-mastoid  muscles.  It  lias  frequently  a  tendinous  intersection  near  its 
insertion. 

NERVE  SUPPLY. — From  the  external  branches  of  the  posterior  divisions  of  the 
spinal  nerves  in  the  thoracic  and  cervical  regions. 

ACTION. — It  Ilexes  the  head  laterally,  rotates  it  to  the  same  side,  and  with  the 
aid  of  its  fellow  extends  the  head. 

The  inner  column  of  the  erector  spiiue  muscle  consists  of  the  spinalis  dorsi 
muscle. 

The  spinalis  dorsi  muscle  is  the  continuation  of  that  portion  of  the  erector 
spina-  muscle  which  arises  from  the  upper  two  lumbar  and  lower  two  thoracic 
spines.  It  is  inserted  into  the  spines  of  the  upper  thoracic  vertebra',  varying  from 
four  to  eight  in  number.  Its  outer  lower  side  is  closely  connected  with  the 
longissimus  dorsi  muscle,  and,  at  its  insertion,  with  the  seini-spinalis  dorsi 
muscle. 

BLOOD  SUPPLY. — From  the  intercostal  and  lumbar  arteries. 

NERVE  SUPPLY. — From  the  posterior  branches  of  the  spinal  nerves  of  the 
thoracic  region. 

ACTION. — It  extends  the  spinal  column  and  flexes  it  laterally. 

The  spinalis  colli  muscle,  analogous  to  the  spinalis  dorsi  muscle,  generally 
extends  from  the  fifth  and  sixth  cervical  spines  to  the  spine  of  the  axis.  It  varies 
considerably,  and  may  be  attached  to  two  additional  spines  below  the  origin  and 
insertion  here  given.  This  muscle  is  not  present  in  all  subjects. 

NERVE  SUPPLY. — From  the  posterior 'branches  of  the  cervical  nerves. 

ACTION. — It  extends  the  neck  and  inclines  it  laterally. 

The  complexus  is  a  broad,  bulky  muscle  occupying  the  cervical  and  upper 
thoracic  regions,  and  passing  upward  and  inward  to  the  occipital  bone.  It  arises 
from  the  posterior  surface  of  the  transverse  processes  of  the  upper  six  thoracic  and 
the  last  cervical  vertebrae,  the  posterior  surface  of  the  articular  processes  of  the 
cervical  vertebrae  (third  to  the  sixth)  and  the  spine  of  the  seventh  cervical  vertebra. 
It  is  inserted  into  the  occipital  bone  between  the  superior  and  inferior  curved  lines. 
Near  the  center  it  has  a  transverse  tendinous  interruption.  It  lies  beneath  the  trape- 
zius  and  the  splenius  muscles,  external  to  the  ligamentum  nuchae,  which  separates 
it  from  its  fellow  of  the  opposite  side,  and  internal  to  the  trachelo-mastoid  and 
26 


SI  RGICAL    A  ^. \T<)MY. 

transversalis  colli  muscles.  It  lies  upon  the  obliquus  capitis  superioris  ami 
inferioris  muscles,  the  rectus  capitis  po-tidis  major  and  minor  muscles,  the  serni- 
spinalis  colli  muscle,  the  profunda  cervicis  and  princeps  cervicis  arteries,  and  the 
posterior  division  of  the  spinal  nerves,  including  the  great  occipital  nerve  which 
pierces  it. 

BLOOD  Srpi-LY. — From  the  profunda  cervicis,  princeps  cervicis,  and  super- 
ficial cervical  arteries. 

NKKVK  SCPI-LY. — From  the  suboccipital,  great  occipital,  and  the  internal 
branches  of  the  posterior  divisions  of  the  third,  fourth,  and  fifth  cervical  nerves. 

ACTION. — It  is  a  powerful  extensor  of  the  head  and  neck,  flexes  the  head 
laterally,  and  turns  the  face  slightly  to  the  opposite  side. 

The  biventer  cervicis,  which  is  the  innermost  portion  of  the  complexus,  is  a 
small,  delicate,  double-bellied  muscle. 

DISSECTION. — The  attachments  of  the  erector  spinse  and  the  spinalis  dorsi 
muscles  to  the  spines  of  the  vertebrae  and  the  insertions  of  the  longissimus  doi>i 
and  the  ilio-costalis  muscles  should  be  severed,  and  the  muscles  reflected  down- 
ward. Next  detach  the  accessorius,  the  cervicalis  ascemlens,  the  transversal!- 
colli,  and  the  trachelo-mastoid  muscle.  Sever  the  complexus  muscle  where  the 
great  occipital  nerve  pierces  it,  preserving  that  nerve  intact  ;  reflect  the  two 
portions,  when  the  suboccipital  and  the  other  nerves  which  enter  its  deep  surface 
will  be  brought  into  view. 

In  reflecting  the  trachelo-mastoid  and  the  complexus  muscle  avoid  injuring 
the  occipital,  princeps  cervicis,  and  profunda  cervicis  arteries,  and  the  deep  cervical 
vein. 

The  occipital  artery  in  the  deepest  part  of  its  course  will  be  found  beneath 
the  mastoid  process  of  the  temporal  bone.  At  this  point  it  is  covered  by  the  origin 

* 

of  the  posterior  belly  of  the  digastric  muscle,  the  mastoid  process,  the  trachelo- 
mastoid,  splenius  capitis  and  sterno-mastoid  muscles.  This  artery  winds  through 
the  interval  between  the  mastoid  process  of  the  temporal  bone  and  the  transverse 
process  of  the  atlas  ;  it  is  separated  from  the  vertebral  artery  by  the  rectus  capitis 
lateralis  muscle,  and  then  traverses  the  occipital  groove  upon  the  mastoid  portion 
of  the  temporal  bone.  It  crosses  the  superior  oblique  and  a  portion  of  the 
complexus  muscle  and  at  the  posterior  border  of  the  splenius  pierces  the  trapezius 
muscle  together  with  the  great  occipital  nerve.  The  vessels  arising  from  this 
portion  of  the  artery  are  the  princeps  cervicis,  the  mastoid,  and  muscular  arteries. 
The  princeps  cervicis  artery  is  given  off  near  the  posterior  border  of  the 
splenius  muscle,  and  divides  into  a  superficial  and  a  deep  branch.  The  superficial 
branch  pierces  the  splenius,  and,  passing  downward  between  that  muscle  and  the 
trape/ius,  anastomoses  with  the  superficial  cervical  artery.  The  deep  branch  passes 


THE    HACK    <>!•'   THE   \ECK,    SHOrLDEH,    AM)    TKl'XK.  40;; 

downward  between  the  complexus  and  semi-spinalis  eolli  muscles  and  anastomoses 
witli  the  profunda  cervicis  artery  and  some  small  branches  of  the  vertebral  artery. 

The  mastoid  branch  passes  through  the  mastoid  foramen  to  supply  the 
mastoid  cells,  the  diploe,  the  walls  of  the  lateral  sinus,  and  the  dura  mater. 

The  muscular  branches  supply  adjacent  muscles. 

The  profunda  cervicis  artery,  a  branch  of  the  superior  intercostal,  emerges 
from  between  the  transverse  process  of  the  last  cervical  vertebra  and  the  neck  of 
the  first  rib,  and,  passing  upward  between  the  complexus  and  the  semi-spinalis 
colli  muscle  anastomoses  with  the  princeps  cervicis  artery  and  branches  of  the 
ascending  cervical  and  vertebral  arteries. 

The  deep  cervical  vein  is  formed  by  small  veins  in  the  suboccipital  triangle, 
usually  receives  the  occipital  vein,  accompanies  the  princeps  cervicis  and  then  the 
profunda  cervicis  artery,  and  empties  into  the  vertebral  or  innominate  vein. 

The  previous  dissection  exposed  the  deepest  muscles  of  the  back  ;  these  are, 
from  below  upward,  the  following  :  The  multifidus  sphue,  the  levatorcs  cost-arum, 
semi-spinalis  dorsi,  semi-spinalis  colli,  the  obliquus  capitis  superioris  and  inferioris, 
the  rectus  capitis  posticus  major  and  minor.  The  middle  layer  of  the  lumbar 
fascia,  the  occipital,  the  princeps  cervicis,  and  the  profunda  cervicis  arteries,  the 
great  occipital  and  suboccipital  nerves,  and  the  suboccipital  triangle  were  also 
revealed. 

BLOOD  SUPPLY. — These  deep  muscles  are  nourished  by  the  vertebral,  princeps 
cervicis,  profunda  cervicis,  intercostal,  and  lumbar  arteries. 

The  semi-spinalis  dorsi  muscle  is  composed  of  small,  fleshy  bellies  uniting 
rather  long  tendons.  It  arises  from  the  transverse  processes  of  the  fifth  to  the 
tenth  thoracic  vertebra;,  and  is  inserted  into  the  spines  of  the  upper  four  thoracic 
and  lower  two  cervical  vertebrae.  It  is  covered  by  the  longissimus  dorsi  and  the 
spinalis  dorsi  muscle,  and  rests  upon  the  multifidus  spinae  muscle. 

NERVE  SUPPLY. — From  the  internal  branches  of  the  posterior  divisions  of  the 
spinal  nerves. 

ACTION. — It  is  an  extensor  and  lateral  flexor  of  the  spinal  column. 

The  semi-spinalis  colli  muscle  is  thicker  and  shorter  than  the  semi-spinalis 
dorsi.  It  arises  from  the  transverse  processes  of  the  upper  five  or  six  thoracic 
vertebrae,  and  is  inserted  into  the  spines  of  the  second  to-  the  fifth  (inclusive) 
cervical  vertebra}.  It  is  covered  by  the  branches  of  the  posterior  division  of  the 
cervical  nerves,  the  princeps  cervicis  and  profunda  cervicis  arteries,  the  deep 
cervical  vein,  and  the  complexus  muscle ;  it  rests  upon  the  multifidus  spinaj 
muscle. 

NERVE  SUPPLY. — From  the  internal  branches  of  the  posterior  divisions  of  the 
spinal  nerves. 


KM  SURGICAL   ANATOMY. 

ACTION. — It  is  an  extensor  and  lateral  flexor  of  the  cervical  portion  of  the 
spinal  column. 

The  levatores  costarum  muscles  arise  from  the  tips  of  the  transverse  pro- 
cesses of  the  last  cervical  and  all  of  the  thoracic  vertebne  except  the  twelfth,  and 
are  inserted  into  the  upper  bonier  and  outer  surface  of  the  next  rib  below,  between 
the  tubercle  and  single.  The  lower  levatores  divide  into  two  slips,  the  additional 
one  going  to  the  second  rib  below.  They  lie  external  to  the  semi-spinalis  dorsi 
muscle. 

NERVE  SUPPLY. — From  the  intercostal  nerves. 

ACTION. — The  levatores,  as  indicated  by  their  name,  elevate  the  ribs,  thus 
assisting  the  external  intercostal  muscles. 

The  multifidus  spin*  muscle  is  situated  in  the  groove  at  the  side  of  the 
spinous  processes,  under  the  semi-spinalis  muscle,  and  extends  from  the  axis  to  the 
sacrum.  The  fibers  arise  from  the  groove  on  the  dorsal  aspect  of  the  sacrum,  the 
posterior  superior  spine  of  the  ilium,  the  posterior  saero-iliac  ligament,  and  the  die)) 
surface  of  the  apoucurotic  origin  of  the  erector  spline  muscle.  In  the  lumbar 
region  the  fibers  arise  from  the  mammillary  processes ;  in  the  thoracic,  from  the 
transverse  processes;  and  in  the  cervical,  from  the  articular  processes  of  the  lower 
four  vertebra1.  From  these  numerous  points  of  origin  the  muscular  bundles  pasa 
upward  in  an  oblique  direction,  and  are  attached  to  the  spinous  processes  and 
lamina?  of  the  vertebra? ;  the  most  superficial  bundles  are  the  longest,  and 
pass  to  the  third  or  fourth  vertebra  above  their  origin  ;  while  the  deeper  ones 
pass  to  the  next  vertebra  and  to  the  second  or  third  above. 

NERVE  SUPPLY. — From  the  internal  branches  of  the  posterior  divisions  of  the 
spinal  nerves. 

The  rotatores  spinae,  situated  under  the  multifidus  spinac  muscle,  are  eleven 
small  quadrilateral  muscles,  each  of  which  arises  from  the  upper  back  part  of  a 
transverse  process  of  a  thoracic  vertebra,  and  ascends  to  be  inserted  into  the  lower 
margin  and  outer  surface  of  the  lamina  of  the  vertebra  immediately  above, 
extending  as  far  inward  as  the  base  of  the  spinous  process. 

NERVE  SUPPLY. — From  the  internal  branches  of  the  posterior  divisions  of  the 
spinal  nerves. 

ACTION. — They  rotate  the  spinal  column,  turning  the  body  of  the  vertebra 
toward  the  opposite  side  ;  and,  acting  bilaterally,  extend  the  spinal  column. 

The  interspinales  muscles  extend  in  pairs  between  contiguous  vertebral 
spines,  the  muscles  of  the  two  sides  being  separated  by  the  interspinous  ligaments. 
There  are  six  cervical  pairs  between  the  axis  and  the  first  thoracic  vertebra,  and 
these  are  the  most  distinct.  Two  or  three  thoracic  pairs  are  found  between  the 
first  and  second  thoracic  spines  above  and  the  eleventh  and  twelfth  below,  and 


PLATE  CIX. 


Rectus  capitis  posticus  minor  m. 
Obliquus  capitis  superioris  m. 


.Occipital  a. 

Suboccipital  n. 


Princeps  cervicis  a. 


Vertebral  a. 


Great  Occipital  n. 
Smallest  occipital  n. 


Posterior  occipito-atlantal  lig. 

Posterior  arch  of  atlas 
Obliquus  capitis  inferioris  m' 
Rectus  capitis  posticus  major  m.' 
Multifidus  Spinae  m. 


Semispinalis  dorsi  m. 


SUBOCCIPITAL  TRIANGLE. 
406 


Till:   BACK    OF   Till-    XM'h;    SHot'I-DEH.    A\I>    TUl'XK.  -l<>7 

~ionally  a  pair  may  be  found  between  the  second  and  third  thoracic  spines. 
There  are  lour  lumbar  pairs  between  ihe  five  lumbar  spines.  Sometimes  there  are 
pairs  ahove  the  iirst  and  below  tin-  last  lumbar  spine. 

NI:I;VK  SrrrLY. —  From  tlie  internal  branches  of  the  posterior  divisions  of  the 
spinal  nerves. 

ACTION. — Thev  assist,  to  a  slight  decree,  ill  extending  the  spinal  column. 

The  intertransversales  muscles  lie  between  the  transverse  processes  of  adjacent 
vertebra'.  There  are  seven  pairs  of  cervical  intertransversales  muscles  on  each  side 
of  the  spinal  column.  They  are  found  between  the  two  adjacent  anterior  and  two 
adjacent  posterior  tubercles,  and  are  separated  by  the  anterior  branch  of  the  cervical 
nerve  emerging  from  the  corresponding  intervertebral  foramen.  They  extend  from 
the  atlas  to  the  Iirst  thoracic  vert  el  mi.  The  ivctus  capitis  lateralis.  extending 
between  the  jugular  process  of  the  occipital  bone  and  the  transverse  process  of 
the  atlas,  corresponds  to  an  inti  rtransversalis  muscle. 

The  Ilini-in-ic  iiitri-ti-iitixiTi'xiih-x  muscles  are  found  only  in  the  lower  three  intervals. 

There  are  four  pairs  of  /inn/mi-  iii1<-,-l,-<tnxi-<  c.«j/Vx  muscles;  of  each  pair,  one 
muscle  connects  the  ends  of  the  transverse  processes,  and  the  other  the  accessory 
tubercle  of  one  vertebra  to  the  mammillary  tubercle  of  the  next  vertebra  below. 

XKIIVK  Sri'i't.v. — From  the  spinal  nerves  as  they  emerge  from  the  interverte- 
bral foramina. 

ACTION. — They  are  lateral  flexors  of  the  spinal  column. 

MOVKMKNTS. — It  will  be  noticed  that  the  muscles  which  permit  movement  of 
the  spinal  column,  or  rather  which  protect  it  against  the  effect  of  too  sudden  and 
extensive  motion,  art'  diminutive  or  absent  in  the  thoracic  region, — the  least 
movable  division  of  the  spinal  column, — and  are  better  developed  in  the  lumbar 
and  cervical  regions,  where  motion  is  much  more  free.  Again,  in' the  neck,  where 
the  movements  are  more  intricate,  these  muscles  are  more  numerous,  and  in  the 
lumbar  region  they  are  much  larger  in  order  to  meet  the  additional  strain  due  to 
the  greater  superimposed  weight. 

The  posterior  cranio-vertebral  muscles  are  the  rectus  capitis  posticus  major 
and  minor  and  obliquus  capitis  superioris  and  inferioris. 

Suboccipital  triangle. — The  rectus  capitis  posticus  major  muscle  with  the 
obli(|nus  capitis  superioris  and  inferioris  muscles  form  the  suhoccipital  triangle. 
This  is  bounded  above  and  to  the  inner  side  by  the  rectus  capitis  posticus  major 
muscle,  above  and  to  the  outer  side  by  the  obliquus  capitis  superioris  muscle,  and 
below  by  the  obliquus  capitis  inferioris  muscle.  The  roof  of  the  triangle  is  formed 
by  the  complexus  muscles,  and  its  floor  by  the  posterior  occipito-atlantal  liga- 
ment and  the  posterior  arch  of  the  atlas.  It  contains  a  small  portion  of  the 
vertebral  artery  and  the  posterior  primary  division  of  the  first  cervical,  or  the 


SURGICAL    .  I  .Y.  I  7YAJ/T. 


suboccipital,  nerve.  The  (•</•/</(,  v//  /1,-f/ri/  in  (lie  suboccipital  triangle  is  seen 
emerging  from  the  transverse  process  of  the  atlas  and  running  above  its  posterior 
arch.  It  leaves  tln>  triangle  by  piercing  the  posterior  occipitoatlantal  ligament. 
The  Kii/iniri/iitii/  neroe  passes  through  the  posterior  occipito-atlantal  ligament  ami 
between  the  verd'hral  artery  and  the  posterior  arch  of  the  atlas.  It  is  small  and 
supplies  the  posterior  reeti,  the  obliqui,  and  the  complexus  muscle. 

The  rectus  capitis  posticus  major  muscle,  cone-shaped,  arises  by  its  apex 
from  the  spine  of  the  axis,  passes  upward,  outward,  and  backward,  and  is  inserted 
by  its  base-  into  the  inferior  curved  line  of  the  occipital  bone  and  the  surface  im- 
mediately below  it.  It  is  covered  by  the  complexus  muscle,  and,  at  its  insertion, 
by  the  superior  oblique  muscle;  it  rests  upon  the  posterior  arch  of  the  atlas,  the 
occipital  bone,  i  he  posterior  occipito-atlantal  ligament,  and  the  rectus  capitis  posticua 
minor  muscle. 

NKHVH  STI-PLY.  —  From  the  suboccipital  nerve. 

ACTION.  —  It  extends  the  head  and  rotates  it  to  the  same  side. 

The  rectus  capitis  posticus  minor  muscle,  triangular  in  shape,  arises  by  its 
apex  from  the  tubercle  upon  the  posterior  arch  of  the  atlas  and  ascends  directly 
upward.  It  is  inserted  into  the  inferior  curved  line  of  the  occipital  bone  and  the 
surface  immediately  below  it.  It  is  covered  by  the  complexus  and  the  ivcms  capitis 
posticiis  major  muscle,  and  lies  upon  the  posterior  occipito-atlantal  ligament. 

XKUVK  SUPIM.Y.  —  From  the  suboccipital  nerve. 

ACTION.  —  It  extends  the  head. 

The  obliquus  capitis  superioris  muscle,  also  triangular  in  shape,  is  smaller 
than  the  inferior  oblique  muscle.  It  arises  by  its  apex  from  the  back  of  the  upper 
surface  of  the  transverse  process  of  the  atlas,  and  passes  upward  and  backward. 
It  is  inserted  into  the  occipital  bone  between  the  two  curved  lines  beneath  the  com- 
plexus muscles.  It  is  covered  by  the  complexus,  the  trachelo-niastoid,  and  the 
splenins  muscles,  and  rests  upon  (he  rectus  capitis  posticus  major  muscle,  vertebral 
artery,  and  posterior  occipito-atlantal  ligament. 

NKUVK  SUPPLY.  —  From  the  suboccipital  nerve. 

ACTION.  —  It  extends  the  head,  ilexes  it  laterally,  and  rotates  the  face  to  the 
opposite  side. 

The  obliquus  capitis  inferioris  muscle,  larger  than  (he  superior  oblique 
muscle,  arises  from  the  spinous  process  of  the  axis  between  (he  attachments  of  the 
rectus  capitis  posticus  major  and  semi-spinalis  colli  muscles.  It  passes  almost 
directly  outward,  and  is  inserted  into  the  tip  of  the  transverse  process  of  the  atlas. 
It  is  covered  by  the  complexus  muscle  and  the  great  occipital  nerve,  —  the  latter 
curving  over  its  lower  margin,  —  and  rests  upon  the  posterior  atlo-axial  ligament 
and  the  vertebral  arterv. 


THE   BACK   OF  THE  XKCK,    SHOULDER,   AND    TRUXK.  409 

NERVE  SUPPLY. — From  the  suhorcipital  nerve. 

ACTION. — It  rotates  the  atlas  upon  the  axis,  carrying  the  face  to  the  same  side. 

The  lumbar  fascia  is  a  dense  aponeurotic  structure  seen  in  the  space  between 
the  last  ril>  and  the  crest  of  the  ilium.  It  assists  in  supporting  the  muscles  of  the 
loin,  and  gives  partial  origin  to  the  internal  oblique  and  transversalis  muscles 
of  the  abdominal  wall.  It  is  attached  above  to  the  last  rib  and  the  cartilage  of  the 
eleventh  rib,  and  below  to  the  posterior  one-third  of  the  crest  of  the  ilium. 
Internally,  it  divides  into  three  layers.  The  posterior  layer  passes  behind  the 
erector  spinre  muscle  and  blends  with  the  aponeuroses  of  the  latissimus  dorsi  and 
serratus  posticus  inferioris  muscles,  which  aponeuroses  are  continued  upward  as  the 
vertebral  fascia.  This  division  of  the  lumbar  fascia  is  attached  to  the  spines  of  the 
lower  thoracic,  lumbar,  and  sacral  vertebras.  The  middle  layer  passes  between  the 
erector  spinse  muscle  and  the  quadratus  lumborum,  and  is  attached  to  the  tips  of 
the  transverse  processes  of  the  lumbar  vertebra?.  The  anterior  layer  passes  in  front 
of  the  quadratus  lumborum,  and  is  attached  to  the  anterior  surface  of  the  bases  of 
the  transverse  processes  of  the  lumbar  vertebra?.  The  upper  portion  of  the  anterior 
layer  which  extends  between  the  transverse  process  of  the  first  lumbar  vertebra  and 
the  tiji  and  lower  border  of  the  last  rib  is  called  the  ligamentum  arc/mtum  (.rt<  mum. 
The  lumbar  fascia  is  overlapped  to  the  outer  side  of  the  erector  spina?  muscle  by 
the  latissimus  dorsi  and  external  oblique  muscles.  It  is  an  important  guide  in 
operations  upon  the  kidney  or  colon  through  the  loin. 

In  lumbar  abscess,  pointing  at  Petit's  triangle,  the  pus  burrows  through  the 
middle  and  posterior  lamellae  of  the  lumbar  fascia. 

The  nerves  of  the  back  are  derived  from  the  posterior  primary  divisions  of 
the  spinal  nerves.  "With  the  exception  of  the  first  and  second  cervical  nerves,  the 
posterior  primary  are  smaller  than  the  anterior  primary  divisions. 

The  posterior  primary  division  of  the  first  cervical  nerve  (suboccipital)  runs 
backward,  pierces  the  occipito-atlantal  ligament,  passes  between  the  vertebral 
artery  and  the  posterior  arch  of  the  atlas  and  through  the  suboccipital  triangle. 
It  supplies  twigs  to  the  rectus  capitis  posticus  major  and  minor  muscles,  the 
obliquus  capitis  superioris  and  inferioris  muscles,  and  the  complexus  muscle.  A 
small  branch  usually  communicates  with  the  great  occipital  nerve. 

The  posterior  primary  division  of  the  second  cervical  nerve  divides  into  an 
external  and  an  internal  branch,  the  latter  being  much  the  larger.  The  external 
branch  sends  a  twig  to  the  inferior  oblique  muscle,  and  then  ends  in  the  com- 
plexus and  the  trachelo-mastoid  muscle.  The  internal  branch  is  called  the  great 
occipital  nerve.  It  sends  twigs  upward  and  downward  which  communicate  with 
the  first  and  third  cervical  nerves,  forming  the  posterior  cervical  plexus  of  Cruveil- 
hier.  The  great  occipital  nerve  then  ascends,  turning  upward  and  backward  over 


IK)  srur.K'M.    .\\ATOMY. 

the  lower  bonier  of  the  inferior  ol>li<|iir  muscle  and  under  cover  of  the  eoni]>lexus. 
It  crosses  over  the  suboccipital  triangle,  pierces  the  complexus  muscle — which  it 
supplies — and  the  outer  bonier  of  the  trape/.ius  near  the  superior  curved  line  of 
the  occipital  bone.  It  then  families  in  the  superficial  fascia  of  the  back  of  the 
scalp  with  the  occipital  artery. 

The  posterior  divisions  of  the  third,  fourth,  and  fifth  cervical  nerves  pass 
backward  at  the  outer  border  of  the  semi-spinali.s  colli  muscle,  and  divide  into 
external  and  internal  branches.  The  c.dcrnul  bi'<m<-li<-x  supply  the  splenius,  the 
trachelo-mastoid.  the  cervicalis  asceiidens,  and  the  !  ransversalis  colli  muscle.  The 
interim!  l>riiiir]ii-K  supply  the  semi-spinalis  colli  and  the  complexus  muscle,  between 
which  they  lie.  and  send  brandies  to  the  multifidus  spline.  They  next  pass 
between  the  complexus  muscle  and  the  liganientum  nuch;e,  pierce  the  origin  of 
the  trapezius  muscle,  and  are  distributed  to  the  integument  of  the  back  of  the 
neck. 

The  smallest  occipital  nerve  is  the  internal  branch  of  the  posterior  division 
of  the  third  cervical  nerve.  It  passes  upward  and  communicates  with  the  great 
occipital  nerve. 

The  external  branches  of  the  posterior  divisions  of  the  sixth,  seventh, 
and  eighth  cervical  nerves  supply  the  splenius,  the  complexus,  the  cervicalis 
asceiidens,  and  the  transversalis  colli  muscle.  The  internal  branches  supply  the 
semi-spinalis  colli  and  the  multifidus  spline  muscle. 

The  posterior  primary  divisions  of  the  thoracic  nerves  pass  backward 
between  the  transverse  processes  of  the  thoracic  vertebra;.  They  then  divide  into 
external  and  internal  branches,  the  former  increasing  and  the  latter  decreasing  in 
size  from  the  second  to  the  last. 

The  external  branr/icx  of  the  posterior  divisions  of  the  upper  six  or  seven  thor- 
acic nerves  terminate  in  the  longissimus  dorsi  and  accessorius  muscles.  The 
lower  five  or  six  pierce  the  outer  insertions  of  the  longissimus  dorsi,  and  are  then 
found  between  that  muscle  and  the  accessorius.  After  piercing  the  latissimus  dorsi 
muscle  they  reach  the  integument  of  the  lower  and  outer  part  of  the  back. 

The  intiriifil  />/-iinfli/-x  supply  the  longissimus  dorsi,  the  spinalis  dorsi,  the 
semi-spinalis  dorsi,  the  multifidus  spline,  the  rotatores  spiine.  the  intertransversales, 
and  the  interspinales  muscles.  The  upper  six  or  seven  branches  pierce  the  origin 
of  the  trapeziua  muscle  and  supply  the  integument. 

The  posterior  divisions  of  the  lumbar  nerves  also  divide  into  external  and 
internal  branches,  the  latter  going  entirely  to  the  multifidus  spiine  muscle.  The 
i.i-fi-rii«l.  /tranches  of  the  upper  three  lumbar  nerves  pierce  the  aponeurosis  of  the 
latissimus  dorsi  near  the  outer  border  of  the  erector  spiine  muscle,  cross  the  crest 
of  the  ilium,  and  are  distributed  to  the  integument  of  the  gluteal  region.  The 


Till-:   BACK   OF   THE  XI-X'K,    SHOULDER,   AXD    THl'XK.  411 


external   branch  of   the  fourth  lumbar  nerve  supplies,  and  that  of  the  fifth 
tci,  the  erector  spin;e  muscle:  the  last  communicates  with  the  first  sacral  nerve. 

The  posterior  primary  divisions  of  the  upper  four  sacral  nerves  emerge  at 
the  posterior  sacral  foramina  ;  that  division  of  the  fifth  sacral  nerve  emerges  at  a 
point  between  the  sacrum  and  coccyx,  and  the  coccygeal  nerve  issues  from  the 
lower  opening  of  the  spinal  canal. 

The  posterior  divisions  of  the  upper  three  sacral  nerves  divide  into  external 
and  internal  branches,  while  the  lower  two  sacral  and  the  coccygeal  nerve  remain 
undivided.  The  external  t/nnn-lics  of  the  posterior  divisions  of  the  upper  three 
sacral  nerves  form  loops  between  themselves  and  the  external  branch  of  the  last 
lumbar  nerve  on  the  back  of  the  sacrum,  and  form  a  second  series  of  loops  on  the 
posterior  surface  of  the  great  sacro-sciatic  ligament.  From  these  loops  are  derived 
two  or  three  nerves  which  pierce  the  glutens  maximus  muscle  to  supply  the  integu- 
ment. The  internal  branches  of  the  posterior  division  of  the  upper  three  sacral 
nerves  supply  the  multifidus  spinaa  muscle.  The  posterior  divisions  of  the  lower 
two  sacral  nerves  form  loops  with  the  coccygeal  nerve  and  the  posterior  branch  of 
the  third  sacral  nerve.  Branches  from  these  loops  supply  the  skin  over  the  coccyx. 

A  careful  study  of  the  groups  of  muscles  of  the  back  will  reveal  the  fact  that 
their  arrangement  is  simpler  than  is  generally  supposed.  The  five  axo-appendicu- 
lar  muscles  —  i.  e.,  the  trape/dus,  latissimus  dorsi,  levator  anguli  scapula?,  and  the 
two  rhomboidei  —  are  well  known.  The  two  posterior  serrati  muscles  are  not 
readily  forgotten.  The  deep  cranio-vertebral  group,  the  two  recti  and  the  two 
oblique  muscles,  are  interesting  and  easily  understood  and  remembered.  The 
erector  spinte  muscle,  with  its  three  upward  extensions,  like  a  spreading  vine, 
picking  its  way,  hand  over  hand,  as  it  were,  from  rib  to  rib,  by  regular  intervals, 
is  not  difficult  to  master  :  The  inner  stem  being  the  spinalis  dorsi  muscle,  the 
middle  consisting  of  the  longissimus  dorsi,  the  transversalis  colli,  and  the  trachelo- 
mastoid  muscle  ;  and  the  outer  stem  being  composed  of  the  ilio-costalis,  the  acces- 
sorius  ad  ilio-costalem,  and  the  cervicalis  ascendens  muscle.  The  complexus  and 
the  biventer  cervicis  really  form  but  one  muscle.  The  semi-spinales  dorsi  and 
colli  muscles  —  extending  by  long  fibers  from  the  transverse  to  the  spinous  pro- 
cesses, over  a  number  of  intervening  vertebrae  —  form  really  one  long,  slender 
group.  The  only  group  remaining  is  formed  by  the  deep  muscles  which  fill  the 
posterior  spinal  groove;  these  extend  —  between  the  spines  (interspinales),  between 
the  transverse  processes  (intertransversales)  —  from  the  dorsal  aspect  of  the  transverse 
processes  of  the  thoracic  vertebra?  to  the  laminae  just  above  (rotatores  spins;),  — 
found  only  in  the  thoracic  region,  —  and  similar  but  more  extensive  muscles 
having  the  same  origins  and  going  to  the  spines  of  the  two  or  three  vertebras 
above  (multifidus  spiiue  muscle). 


M'2  SURGICAL    ANATOMY. 

LIGA.MKXTs    OF    Till-:   I  '/•;/,' 7V-; /,'/.'. I  L   COLUMN. 

Tlu1  ligaments  uniting  the  vertebra1  may  IK'  divided  as  follows  :  Those  con- 
necting tin-  bodies;  the  lamina-;  tin-  spinous  processes ;  the  transverse  processes, 
and  the  articular  processes  of  the  vcrteline. 

The  Ligaments  which  Unite  the  Bodies  of  the  Vertebrae  are  the  anterior 
and  posterior  common  ligaments,  the  intervertebral  discs,  and  the  lateral  vertebral 
ligaments. 

The  anterior  common  ligament  is  a  fibrous  band  which  is  situated  upon  the 
anterior  surface  of  the  bodies  of  the  vertebra,  and  extends  from  the  tubercle  upon 
the  anterior  arch  of  the  atlas  to  the  front  of  the  middle  piece  of  the  sacrum. 
Above,  it  is  narrow  and  forms  the  central  portion  of  the  atlanto-axoid  ligament. 
As  it  descends  it  broadens  and  forms  a  glistening  white  investment  for  the  anterior 
surface  of  the  bodies  of  the  vertebra?.  Below,  it  is  attached  to  the  front  of  the 
sacrum,  and  is  lost  in  the  periosteum  of  that  bone.  It  is  continued  as  the  anterior 
sacro-coccygeal  ligament.  The  ligament  is  composed  of  numerous  fibers  of  various 
lengths.  The  most  superficial  fibers  extend  over  four  or  five  consecutive  vertebrae, 
deeper  ones  over  two  or  three  vertebra',  and  the  deepest  connect  adjacent  vertebra;. 
The  fibers  of  these  different  lengths  are  so  interlaced  that  it  is  impossible  to  sepa- 
rate the  ligament  into  these  three  sets  of  fibers.  The  ligament  is  closely  attached 
to  the  intervertebral  discs  and  the  edges  of  the  bodies  of  the  vertebra;,  but  is  not 
so  firmly  united  with  the  intermediate  portion  of  the  bodies.  It  is  thickest  in  the 
thoracic  region,  and  in  the  lumbar  is  thicker  than  in  the  cervical  region. 

The  posterior  common  ligament  is  located  upon  the  posterior  surface  of  the 
bodies  of  the  vertebra?  and  lines  the  anterior  wall  of  the  spinal  canal.  It  extends 
from  the  basilar  groove  of  the  occipital  bone  to  the  coccyx  ;  is  broader  above  than 
below,  and  thickest  in  the  thoracic  region  :  presenting  opposite  the  intervertebral 
discs  lateral  expansions  which  give  it  a  dentated  appearance.  Between  the  liga- 
ment and  the  middle  of  the  posterior  surface  of  bodies  of  the  vertebne  is  an 
interval  which  is  occupied  by  some  areolar  tissue  and  vessels  to  the  bodies  of  the 
vertebne.  The  filum  terminate  of  the  spinal  cord  blends  with  the  ligament  at 
the  back  of  the  base  of  the  coccyx.  The  more  superficial  fibers  extend  between 
three  or  four  vertebne,  and  the  deeper  ones  between  adjacent  vertebrae. 

The  intervertebral  substance  or  intervertebral  discs  arc  twenty-three  in 
number,  situated  between  the  adjacent  surfaces  of  the  bodies  of  the  vertebra- 
from  the  axis  to  the  sacrum.  They  are  tough,  elastic,  and  compressible,  and  form 
the  chief  bond  of  union  between  the  vertebra1.  In  the  sacral  region  they  are  more 
or  less  completely  ossified.  They  are  flattened  or  rather  wedge-shaped,  and  their 
outline  corresponds  to  that  of  the  adjacent  vertebral  bodies.  In  the  thoracic  region 


PLATE  CX. 


Posterior  Common  Lig. 


Inter-Vertebral 
Substance. 

Pulpy  Centre. 


Anterior 
Common  Lig 


Vena  Basis 
Vertebrae. 


Spinous  Process. 


Supra-Spinous 
Lig- 


Capsular  Lig. 


Interspinous 
Lig. 

Ligamentum 
Subflavum. 


LIGAMENTS  OF  SPINAL  COLUMN. 
413 


LIGAMKMV   01-'   T1IH   VERTEBRAL    C'OLI'MX.  415 

their  thickness  is  nearly  uniform,  and  the  thoracic  curve  is  chiefly  formed  by  tin- 
bodies  of  the  vertebra-,  and  in  the  cervical  and  lumbar  regions  their  greater 
thickness  in  front  assists  in  forming  the  curves  of  (hose  portions  of  (he  spinal 
column.  They  form  about  one-fourth  of  the  length  of  the  spinal  column,  and 
are  thickest  and  largest  in  the  lumbar  region.  When  they  are  shrunken  or 
compressed,  as  in  old  persons  or  laborers,  the  spinal  column  shortens  and  bends 
forward.  They  are  composed  of  a  firm  ring  of  fibro-cartilaginous  tissue  and  a 
central  pulpy  substance.  The  fibro-cartilaginous  tissue  is  arranged  in  concentric 
lamiiue,  the  fibers  of  which  pass  obliquely  from  one  surface  of  the  disc  to  the 
other.  The  directions  of  the  fibers  of  the  two  adjacent  laminae  are  not  parallel, 
but  form  angles  like,  the  limbs  of  the  letter  X.  The  central  substance  of  the 
discs  is  of  a  pulpy  consistency,  and  is  composed  of  a  fine  connective-tissue  matrix 
which  contains  cartilage  cells  in  its  meshes. 

The  lateral  or  short  vertebral  ligaments  connect  the  adjacent  margins  of 
the  bodies  of  the  vertebra  in  the  interval  between  the  anterior  and  posterior 
common  ligaments,  with  which  they  are  continuous.  They  are  best  developed  in 
the  thoracic  and  lumbar  regions. 

The  Laminae  are  connected  by  the  ligamenta  subflava, 

The  ligamenta  subflava  are  found  in  the  spaces  between  and  connecting  the 
lamina?  of  the  vertebrae.  The  first  of  these  ligaments  extends  from  the  axis  to  the 
third  cervical  vertebra,  the  two  spaces  above  being  filled  by  the  posterior  occipito- 
atlantal  and  posterior  atlanto-axoid  ligaments.  The  ligamenta  subflava  are 
attached,  above,  to  the  inner  surface  of  the  inferior  articular  process  and  the  inner 
surface  of  the  lower  margin  of  the  lamina  of  the  vertebra ;  below,  to  the  inner 
surface  of  the  superior  articular  process  and  the  upper  margin  of  the  lamina. 
Each  ligament  extends  from  the  articular  processes  of  one  side  to  those  of  the 
opposite  side,  forming  one  broad,  short  ligament.  These  ligaments  assist  in 
forming  the  capsular  ligaments,  which  connect  the  articular  processes  and  are 
continuous  with  the  interspinous  ligaments  at  the  roots  of  the  spinous  processes. 
They  are  strongest  in  the  lumbar  region,  of  greater  strength  in  the  thoracic 
than  in  the  cervical  region,  are  composed  of  yellow  elastic  tissue,  and  assist  in 
retaining  the  spinal  column  in  the  erect  position. 

The  Spinous  Processes  are  connected  by  the  supra-spinous  and  interspinous 
ligaments. 

The  supra-spinous  ligaments  connect  the  tips  of  the  spinous  processes,  and 
present  the  appearance  of  a  strong,  narrow,  continuous  band  extending  from  the 
seventh  cervical  vertebra  (vertebra  prominens)  to  the  spinous  processes  of  the 
sacrum.  They  are  continued  upward  as  the  ligamentum  nuchse  and  downward 
along  the  spines  of  the  sacrum.  The  downward  continuation  of  the  supra-spinous 


SURGICAL    .\\.Crti.MY. 
ligaments  closes  in  the  lower  end  of  the  spinal  canal,  and  is  attached  to  the  back 

of   the  coccyx. 

The  interspinous  ligaments  are  thin,  membranous  sheds  which  connect 
adjacent  spinous  processes  of  the  vertebra?.  The  fibers  of  each  ligament  decussate. 
They  arc  stronger  in  the  lumbar  than  in  the  thoracic  region,  and  in  the  cervical 
region  are  delicate  and  supported  by  the  interspinales  mii-cles. 

The  Transverse  Processes  are  connected  by  the  intertransverse  ligaments. 

The  intertransverse  ligaments  pass  between  the  tips  of  the  transverse  pro- 
-e.s.  In  the  thoracic  region  they  are  weak  bands;  in  the  lumbar  region  they 
are  weak  and  membranous;  and  in  the  cervical  region  they  are  replaced  by  the 
intertransversales  muscles. 

The  Articular  Processes  are  connected  by  capsular  ligaments. 

The  capsular  ligaments  connect  adjacent  articular  processes  and  are  attached 
along  the  margins  of  the  articulating  surfaces.  Their  inner  portion  is  formed  by 
the  lateral  part  of  the  ligamenta  subflava.  In  the  cervical  region  they  are  loose; 
in  the  lumbar  region  not  so  lax  ;  and  in  the  thoracic  region  short  and  tight. 
Kach  joint  is  lined  by  one  synovial  membrane. 

MOVEMENTS. — The  spinal  column  is  the  axis  of  the  skeleton;  it  supports  the 
cranium,  upper  extremities,  and  part  of  the  trunk,  and  is  supported  by  the  pelvis 
and  lower  extremities.  It  is  composed  of  a  number  of  bones,  one  superimposed 
upon  another  and  bound  together  by  numerous  strong  ligaments.  When  assisted 
b\-  the  surrounding  muscles,  it  is  capable  of  sustaining  great  weight,  and  by  means 
of  their  elasticity  the  intervertible  discs  diminish  or  prevent  the  transmission  of 
shock.  Although  the  vertebnc  are  iirmly  united  and  then.'  is  little  movement 
between  adjacent  vertebra?,  the  spinal  column  is  quite  flexible  and  capable  of 
many  movements;  these  are  possible  on  account  of  the  elasticity  of  the  inter- 
vertebral  substance,  and  all  occur  around  an  axis  which  passes  through  the 
central  pulpy  substance  of  the  intervertebral  discs.  The  movements  vary  in 
different  regions,  and  their  freedom  differs  with  the  shape  of  the  bodies,  the  articu- 
lar, transverse,  and  spinous  processes.  The  bodies  and  intervening  discs  are  the 
chief  supports  of  the  superimposed  weight,  and  the  articular  processes,  assisted  by 
the  ligaments  between  the  spines  and  between  the  transverse  processes,  steady 
the  column.  The  movements  are  flexion,  extension,  lateral  flexion,  cireumduc- 
tion,  and  rotation. 

In  the  neck  there  is  little  movement  between  the  axis  and  the  third  cervical 
vertebra,  but  below  this  vertebra  all  movements  are  free  in  this  region.  Flexion 
is  more  limited  than  in  the  lumbar  region. 

In  the  thoracic  region  there  is  slight  movement,  because  of  the  obstruction 
offered  by  the  ribs. 


PLATE  CXI. 


Occipito-Atlantal 
Capsular  I,iV. 

Anterior  oblique 
Occipito-Atlautal 


Atlanto-Axoidean 
Capsular  Lig. 
Anterior  AtlantO' 
Axoidean  Lig. 

Body  of  Axis 


Capsular  Lig.  between  \ 

articular  processes  of  I 

Axis  and  third  [ 

Cervical  Vertebra.  I 


Superficial  portion  of 
Anterior  Occipito- 
Atlantal  Lig. 

Anterior  Occipito- 
Atlantal  Lig. 


Atlanto-Axoidean 
Synovial  membrane. 


Anterior  Common 
Lig. 

Short  Vertebral 
Lig. 


ANTERIOR    VIEW. 


Anterior  Oblique 
or  Lateral  Occipito- 
Atlantal  Lig. 


Posterior  Occipito- 
Atlantal  Lig. 


Posterior  Arch 
of  Atlas 

Lamina  of  Axis 


Posterior  Atlanto- 
Axoidean  Lig. 

Atlanto-Axoidean  Capsular 
Lig.  and  Synovial  Membrane. 

Ligamentum  Subflavum. 


27 


POSTERIOR    VIEW. 

OCCIPITO-ATLANTAL  AND  ATLANTO-AXOIDEAN   LIGAMENTS. 
117 


LIGA.M]-:.\TS   OF   Till:    VFAlTFAUtAL    rul.l'MX.  41!) 

In  the  lumbar  region  all  of  the  movements  are  comparatively  free  between 
the  third  and  fourth,  and  fourth  and  tilth  vertebra-. 

As  the  forms  of  the  joints  between  the  occipital  bone,  atlas,  and  axis  differ 
from  those  of  the  intervertehral  joints  below,  they  require  a  separate  description. 

The  Axis  is  Connected  with  the  Atlas  by  the  anterior  and  posterior  atlanto- 
axoid.  two  eapsuhir,  transverse,  and  atlanto-odontoid  capsular  ligaments,  and 
between  them  are  two  lateral  and  one  central  atlanto-axoid  joint. 

The  anterior  atlanto-axoid  ligament  is  a  thin,  fibre-elastic  membrane.  It  is 
attached  above  to  the  anterior  surface  and  lower  border  of  the  anterior  arch  of  the 
atlas,  and  below  to  the  base  of  the  odontoid  process  and  the  transverse  ridge  on 
the  front  of  the  body  of  the  axis.  Its  median  portion  is  covered  by  the  narrow 
upper  end  of  the  anterior  common  ligament,  which,  in  this  location,  is  sometimes 
called  the  superficial  anterior  atlanto-axoid  ligament.  On  either  side  the  atlanto- 
axoid  ligament  is  continuous  with  the  capsular  ligaments.  It  is  covered  by  the 
longus  colli  muscles. 

The  posterior  atlanto-axoid  ligament  is  a  thin  membrane  which  takes  the 
place  of  the  ligamenta  subflava  in  this  location.  It  is  attached  above  to  the 
posterior  surface  and  lower  margin  of  the  posterior  arch  of  the  atlas  and  below  to 
the  dorsal  aspect  of  the  superior  margins  of  the  lamina  of  the  axis.  On  either 
side  it  extends  to  the  posterior  roots  of  the  transverse  processes,  and  is  continuous 
with  the  capsular  ligaments.  It  is  covered  by  the  rectus  capitis  postieus  major 
and  obliquns  capitis  inferioris  muscles. 

The  lateral  atlanto-axoid  joints  are  formed  by  the  articulation  of  the 
superior  articular  processes  of  the  axis  with  the  inferior  articular  surface  of  the 
lateral  mass  of  the  atlas.  Each  joint,  has  a  loose  capsular  ligament  and  one 
synovial  sac.  The  ligaments  are  strengthened  in  front  and  behind  by  the  anterior 
and  posterior  atlanto-axoidean  ligaments. 

The  central  atlanto-axoid  joint  is  divisible  into  two  joints — one  between  the 
odontoid  process  of  the  axis  and  the  transverse  ligament  (syndesmo-odontoid)  and 
the  other  between  the  odontoid  process  and  anterior  arch  of  the  atlas  (atlanto- 
odontoid).  Each  of  these  joints  has  a  synovial  membrane.  The  s}rnovial  sac  of 
the  syndesmo-odontoid  joint  is  limited  by  a  fibrous  membrane  which  passes  from 
the  transverse  ligament  to  the  margins  of  the  articular  facet  upon  the  posterior 
surface  of  the  odontoid  process  and  thus  forms  a  capsular  ligament.  This  synovial 
sac  often  communicates  with  the  occipito-atlantal  synovial  sacs.  The  synovial  sac 
of  the  atlanto-odontoid  joint  is  supported  by  the  atlanto-odontoid  capsular  liga- 
ment, which  passes  between  the  margins  of  the  articular  surface  upon  the  anterior 
aspect  of  the  odontoid  process  and  those  of  the  articular  surface  upon  the  internal 
surface  of  the  anterior  arch  of  the  atlas.  The  atlanto-odontoid  capsular  liga- 


)•_'()  SURGICAL    .-l.y 

ment  is  continuous  with  the  occipito-atlantal  eapsular  ligaments.  At  thr  margins 
of  the  uivh  of  ihe  atlas  it  blends  \vitli  the  central  occipito-odontoid,  anterior 
occipito-atlantal,  and  anterior  atlanto-axoid  ligaments. 

The  transverse  ligament  is  a  strung,  closely  woven,  fibrous  band  which 
passes  across  the  large  central  opening  in  the  arch  of  the  atlas,  and  divides  it  into 
a  small  anterior  portion — through  which  the  odontoid  process  projects — and  a 
large  posti-rior  part,  which  is  the  upper  continuation  of  the  spinal  canal  and 
transmits  the  spinal  cord,  its  membranes,  and  the  spinal  portion  of  the  spinal 
accessory  nerves.  I'pon  each  side  the  transverse  ligament  is  attached  to  the 
tubercle  upon  the  inner  surface  of  the  lateral  mass  of  the  atlas.  A  vertical  band 
of  fibers,  placed  immediately  behind  the  transverse  ligament,  passes  from  the  back- 
part  of  the  base  of  the  odontoid  process  to  the  occipital  bone.  This  band  is 
Mreiiglhened  by  fibers,  some  of  which  pass  upward  and  others  downward  from 
the  transverse  ligament.  The  transverse  ligament  and  the  vertical  band  form  a 
crucial  ligament.  The  anterior  surface  of  the  transverse  ligament  is  smooth  and 
in  relation  with  the  syndesmo-odontoid  synovial  membrane.  The  lower  margin  of 
the  ligament  is  closely  apposed  to  the  neck  of  the  odontoid  process  and  thus  firmly 
suspends  that  process  in  place. 

MOVKMKNTS. — The  movements  between  the  atlas  and  axis  are  necessarily 
chiefly  in  a  rotatory  direction.  These  movements  are  limited  by  the  occipito-axoid 
(check)  and  the  atlanto-axoid  ligaments.  The  movement  in  the  lateral  atlanto- 
axoid  joints  is  of  a  gliding  character.  There  is  also  slight  antero-posterior  and 
lateral  flexion. 

The  Ligaments  which  Connect  the  Axis  with  the  Occipital  Bone  are  the 
occipito-cervical,  crucial,  and  three  odontoid  ligaments. 

The  occipito-cervical,  cervico-basilar,  or  occipito-axoid  ligament  is  the 
upper  portion  of  the  posterior  common  ligament,  some  of  the  fibers  of  which  are 
not  attached  to  the  axis  but  pass  upward  to  the  occipital  bont>.  The  ligament  is 
attached  below  to  the  posterior  surface  of  the  body  of  the  axis  from  the  root  of  the 
odontoid  process  downward,  and  its  lower  attachment  also  extends  to  the  upper 
part  of  the  body  of  the  third  cervical  vertebra.  Above,  it  is  attached  to  the 
basilar  groove  of  the  occipital  bone.  It  is  narrow  at  the  body  of  the  axis  and 
gradually  broadens  above.  It  is  in  relation  in  front  with  the  crucial  ligament,  and 
behind  with  the  dura  mater  of  the  spinal  cord,  and  is  exposed  by  removing  the 
spines  and  laminie  of  the  atlas  and  axis. 

The  crucial  ligament  is  described  with  the  transverse  ligament. 

The  odontoid  ligaments  connect  the  odontoid  process  with  the  occipital  bone. 
They  are  three  in  number — viz.,  a  central  and  two  lateral. 

The  central  odontoid  ligament,  or  suspensory  lii/mur//!,  is  attached  below  to  the 


PLATE  CXil. 


Posterior  Common  Lig. 


Cervico-Basilar  Lig. 


Vertical  Portion) 

of  Transverse  or  I 

Crucial  Lig-/ 


Atlanto-Axoidean 
Capsular  Lig. 


Cervico-Basilar  Lig 


Central 
Occipito-Odontoid  Lig. 


Lateral  Occipito- 
Odontoid  Lig. 


Transverse  Lig. 


Occipito-Atlantal 
Capsular  Lig.  and 
Synovial  Membrane. 


Posterior  Common  Lig. 


LIGAMENTS   IN   POSTERIOR  SURFACE  OF  UPPER  PART  OF  ANTERIOR  WALL  OF  SPINAL  CANAL. 


Transverso-Odontoid 
Synovial  Sac. 


Odontoid  Process. 


Lateral  Occipito- 
Odontoid  Lig. 


Vertical  Portion  of 

Transverse  or  Crucial 

Lig. 


Atlanto-Odontoid 
Synovial  Sac. 


Central  Occipito- 
Odontoid  Lig. 


Transverse  Lig. 


CENTRAL  ATLANTO-AXOID  JOINT. 
421 


/.A/.u//-:.Y7N  OF  nil-:  vr.nrr.nnM.  COLUMN.  4-2:} 

tip  of  the  odontoid  process  and  above  to  the  under  surface  of  the  anterior  margin 
of  tlie  foramen  magnum.  It  is  a  slender  hand  which  is  located  between  the  two 
lateral  odontoid  ligaments.  It  is  in  relation  in  front  with  the  anterior  occipito- 
atlantal.  and  behind  with  the  upper  division  of  the  crucial  ligament. 

The  lulu -it!  iii/iiiitniil,  nr  dark,  /!</<iiiicnfx  arc  strong,  rounded  bands  which  pass 
almost  transversely  outward  and  slightly  upward  from  the  sides  of  the  apex  of  the 
odontoid  process  to  the  rough  depressions  upon  the  inner  surfaces  of  the  condyh  ~ 
of  the  occipital  hone. 

The  Ligaments  which  Connect  the  Atlas  with  the  Occipital  Bone  are  the 
anterior  and  posterior  occipito-atlantal,  two  capsular,  and  two  lateral  occipito 
atlantal  ligaments. 

The  anterior  occipito-atlantal  ligament  is  attached  below  to  the  upper 
margin  of  the  anterior  arch  of  the  atlas,  and  above  to  the  anterior  margin  of  the 
foramen  magnum.  Its  central  portion  is  thick  and  strong,  and  is  the  upward 
continuation  of  the  anterior  common  ligament.  The  lateral  portions  of  the  liga- 
ment are  thinner  and  continuous  with  the  capsular  ligaments.  It  is  covered  in 
front  by  the  rectus  capitis  anticus  minor  muscles.  Behind  it  are  the  odontoid 
ligaments. 

The  posterior  occipito-atlantal  ligament  is  a  thin  membrane  and  corresponds 
to  the  ligamenta  subflava,  but  contains  no  elastic  tissue.  Its  laxity,  however, 
permits  free  motion.  The  ligament  is  attached  below  to  the  posterior  surface  and 
upper  margin  of  the  posterior  arch  of  the  atlas,  and  above  to  the  posterior  margin 
of  the  foramen  magnum  from  one  condyle  to  the  other.  Upon  each  side  its  lower 
and  outer  portion  contains  an  opening  close  to  the  arch  of  the  atlas.  This  opening 
gives  passage  to  the  vertebral  artery  and  suboccipital  nerve.  In  front  the  ligament 
is  in  relation  with  the  dura  mater,  and  behind  with  the  rectus  capitis  posticus 
minor  and  superior  oblique  muscles. 

The  two  capsular  ligaments  are  attached  to  the  margins  of  the  condyles  of 
the  occipital  bone  above,  and  below  to  the  margins  of  the  articular  surfaces  upon 
the  upper  aspect  of  the  lateral  mass  of  the  atlas.  These  ligaments  arc  lax  and 
not  very  strong,  and  therefore  do  not  add  much  strength  to  the  joint.  Each 
capsular  ligament  is  lined  with  a  synovial  membrane  which  occasionally  commu- 
nicates with  the  synovial  sac  of  the  transverse-odontoid  joint. 

The  lateral  occipito-atlantal  or  anterior  oblique  occipito-atlantal  ligaments 
are  two  strong  fibrous  bands  placed  upon  the  front  of  the  external  surface  of  the 
capsular  ligament.  They  pass  from  the  bases  of  the  transverse  processes  of  the 
atlas  forward  and  upward  to  be  attached  to  the  jugular  processes  of  the  occipital 
bone. 

MOVEMENTS. — The  movements  of  the  occipito-atlantal  articulations  are  gliding 


|-_M  >T/,V//r,l/,    A  y  ATOMY. 


backward  Mini  forward.  tints  giving  a  limited  nodding  movement  to  tin-  head. 
In  more  extensive  forward  MIK!  backward  movements  of  the  head  the  cervical 
])ortioii  of  the  spinal  column  is  flexed  and  extended.  There  is  also  a  verv  slight 
transverse  and  oblique  gliding  moveiiu'tit. 

I>i.n<>n  Srri'LY.  —  The  Mood  supply  of  the  spinal  column  and  its  articulations 
is  derived  from  the  vertebral,  occipital,  ascending  pharyngeal.  ascending  cervical, 
intercostal,  luinhar.  ilio-luniliar.  sacra-media,  and  lateral  sacral  arteries. 

NKKVK  SrriM.Y.  —  From  the  spinal  nerves. 

Fractures  and  dislocations  of  the  vertebra  are  most  common  in  the  cervical 
and  lumbar  regions  where  mobility  of  the  spinal  column  is  greatest.  If  displace- 
ment exists,  the  spinal  cord  is  compressed,  lacerated,  or  pnlpiiied.  Pressure  upon 
or  laceration  of  the  motor  tracts  of  the  spinal  cord  causes  loss  of  voluntary  motion 
in  muscles  supplied  by  nerves  which  arise  below  the  site  of  injury,  because  the 
motor  cells  of  the  cerebral  cortex  can  not  send  impulses  to  the  motor  cells  in  or 
below  the  injured  segments  of  the  spinal  cord.  Sensation  in  the  paralyzed  parts  is 
lost  through  involvement  of  the  sensory  tracts  of  the  spinal  cord  and  interruption 
of  the  impulses  to  the  brain.  Through  pressure  upon  or  rupture  of  the  inhibitory 
nerves  from  the  brain  the  relle.xes  are  not  controlled  and  are  much  exaggerated 
unless  the  lumbar  enlargement  be  destroyed.  Pressure  upon  the  inhibitory  nerves 
for  this  reason  causes  priapism.  Through  pressure  upon  the  trophic  nerves  nutri- 
tion of  the  skin  is  imperfect  and  bed-sores  develop.  Loss  of  trophic  and  motor 
impulses  allows  degeneration  and  atrophy  of  the  muscles.  Through  pressure  upon 
the  sensory  and  motor  tracts  fullness  of  the  bladder  causes  no  reflex  act,  and  reten- 
tion of  urine  results.  After  some  time  elapses  the  function  of  micturition  may  be 
performed  through  reflex  action  governed  by  the  cells  in  the  lower  portion  of  the 
spinal  cord.  Paralysis  of  the  sphincter  ani  causes  incontinence  of  feces. 


DISSECTION. — Having  finished  the  study  of  the  muscles  of  the  back,  the 
student  should  thoroughly  clean  the  posterior  aspect  of  the  vertebra'  from  the 
skull  to  the  base  of  the  sacrum.  In  removing  the  muscles,  care  must  be  taken  to 
avoid  destroying  the  posterior  divisions  of  the  spinal  nerves  which  supply  them. 
The  posterior  wall  of  the  spinal  canal  should  then  be  removed  in  one  piece.  To 
accomplish  this,  place  the  body  upon  the  table,  face  downward,  the  head  hanging- 
over  tin-  edge,  and  a  block  under  the  abdomen  :  saw  through  the  lamh:;c  of  the 
vertebrae. on  each  side  close  to  the  bases  of  the  spinous  processes  from  the  third 
cervical  to  the  last  lumbar,  inclusive.  The  ligaments  between  the  spinous  pro- 
cesses and  between  the  lamina'  of  the  second  and  third  cervical,  and  between  the 


PLATE  CXIII. 


Posterior  Longitudinal 
Meningo-Rachidean 
Veins. 


(Anterior  Longitudinal 
\Meningo-Rachidean  Vein. 

Vena  Basis  Vertebrae. 


Dorsi- Spinal  Veins 


Posterior  Longitudinal 
Meningo-Rachidean  Vein 


Intercostal  V. 


Anterior  Longitudinal        \\. 
Meningo-Rachidean  Vein. 
Veins. 


Intervertebral  Disc. 


Spinal  Canal. 

Intercostal  V. 

Vena  Basis  Vertebrae. 


(Anterior  Longitudinal 
JMeningo-Rachidean 
Veins. 


SPINAL  VEINS. 
425 


All  TEH  //•>'  A\D   VEL\S   OF   Till'.    1 7.7/77-;/,1 /,'.!/.    COLUMN.  ±11 

same  portions  dt'  the  last  lumbar  and  first  sacral  verteline,  should  he  divided  with 
the  knife,  and  the  posterior  wall  of  the  canal  lifted  out.  This  will  expose  n 
(|iiantity  of  loose  areolar  tissue  and  fat  which  contains  plexuses  of  veins  and  some 
small  arteries.  Carefully  remove  the  areolar  tissue  and  fat, 

The  Spinal  Arteries. — The  blood  supply  of  the  spinal  column,  spinal  liga- 
ments, periosteum,  and  of  the  spinal  cord  and  its  membranes  is  derived  from 
the  spinal  arteries  which  enter  the  canal  through  the  inierverteliral  foramina. 
The  spinal  arteries  in  the  cervical  region  are  derived  from  the  vertebral,  ascending 
cervical,  and  profunda  cervicis  arteries;  in  the  thoracic  region,  from  the  dorsal 
branches  of  the  intercostal  arteries;  in  the  lumbar  region  from  the  posterior 
brandies  of  the  lumbar  arteries;  and  in  the  sacral  region  from  the  lateral  sacral 
arteries.  The  arrangement  of  the  arteries  after  entering  the  spinal  canal  is  similar 
in  the  different  regions.  Each  spinal  artery  divides  into  three  branches — one  of 
which  passes  to  the  vertebral  arches  and  ligamenta  subflava  :  another  pierces  the 
dura  mater  above  the  corresponding  spinal  nerve,  and  supplies  the  spinal  cord  and 
its  membranes;  and  a  third  passes  to  the  posterior  surface  of  the  bodies  of  the 
vertebra1.  Tin1  small  plexuses  of  arteries  seen  on  the  posterior  aspect  of  the  bodies 
of  the  vertebra'  are  formed  by  the  divisions  of  the  third  set  of  branches  which 
anastomose  with  each  other.  These  plexuses  also  give  off  branches  which  pass 
anteriorly  around  the  wall  of  the  canal  to  join  branches  from  a  median  artery 
found  on  the  posterior  surface  of  the  anterior  common  ligament, 

The  Veins  found  Within  the  Spinal  Canal  are  the  meningo-rachidian  and 
the  medulli-spinal  veins.  The  meningo-rachidian  veins  lie  in  the  extra-dural 
fat,  and  are  arranged  in  two  plexuses — one  anterior  and  one  posterior.  The  ante- 
rior plexus,  of  course,  can  not  be  studied  until  the  spinal  cord  and  its  membranes 
have  been  removed  from  the  spinal  canal.  It  consists  of  two  longitudinal  veins 
which  communicate  freely  with  each  other  by  means  of  transverse  veins  which 
pass  beneath  the  posterior  common  ligament  and  receive  the  veins  from  the  bodies 
of  the  vertebra?  (venae  basis  vertebrae).  The  anterior  plexus  communicates  with 
the  basilar  and  occipital  sinuses.  Near  the  arch  of  the  atlas  it  gives  off  a  branch 
which  forms  the  origin  of  the  vertebral  vein.  Other  branches  are  given  off  near 
the  intervertebral  foramina,  and  accompany  the  spinal  nerves.  The  posterior 
longitudinal  plexus  consists  of  two  longitudinal  veins  or  channels,  placed  upon 
the  inner  surface  of  the  lamina;.  Branches  pass  freely  from  one  channel  to  the 
other  ;  others  pierce  the  ligamenta  subflava  to  communicate  with  the  dorsi-spinal 
veins  ;  while  other  branches  pass  forward  to  join  the  anterior  plexus,  thus  forming 
a  network  which  entirely  encircles  the  spinal  cord.  The  posterior  plexus  commu- 
nicates with  the  occipital  sinus. 

The  medulli-spinal  veins  are  described  with  the  spinal  cord. 


SURGICAL   ANATOMY. 


TIIK  SPINAL  CORD. 

The  spinal  cord   (medulla   spinali.-i  is  the  continuation  of  the  medulla  oblon- 

gata.  It  extends  from  tin-  lower  border  of  the  foramen  magnum  (below  the 
deeussatiou  of  the  pyramids  of  the  medulla)  to  the  level  of  the  upper  hurder  <>f 
the  second  lumbar  vertebra  ;  near  its  termina.tion  it  assumes  a  conic  shape,  —  the 
conus  medullaris,  —  and  terminates  in  a  slender  thread,  the  filum  terminate.  In 
the  fetus  the  cord  extends  the  entire  length  of  the  spinal  canal,  hut  does  not  in 
the  adult,  as  the  vertebral  column  prows  more  rapidly  than  the  spinal  cord. 
The  length  of  the-  spinal  cord  in  the  adult  is  from  sixteen  to  eighteen  inches. 
and  its  average  weight  is  ahout  one  and  one-half  ounces.  It  is  a  somewhat 
flattened  cylinder,  wider  in  the  transverse  diameter.  In  the  thoracic  region,  how- 
ever, it  is  almost  cylindric  in  form.  As  it  is  lodged  in  the  spinal  canal,  it  follows 
the  curves  of  the  spinal  column.  It  presents  a  cervical  enlargement  hot  ween  the 
third  cervical  and  second  thoracic  vertebra-,  and  a  lumbar  enlargement  between 
the  ninth  thoracic  and  the  first  lumbar  vertebra.  The  former  enlargement  is 
widest  opposite  the  sixth  cervical,  and  the  latter  opposite  the  twelfth  thoracic 
vertebra.  These  enlargements  occur  where  the  large  nerves  are  given  off  to 
supply  the  extremities. 

The  Membranes  of  the  Spinal  Cord.  —  The  membranes  of  the  spinal  cord  are 
the  dura  mater,  arachnoid,  and  pia  mater.  They  are  continuous  with  the  corres- 
ponding membranes  of  the  brain,  and  hold  the  same  relation  to  each  other  as  do 
those  of  the  brain. 

The  dura  mater  is  a  non-adherent,  dense,  fibrous  sheath  which  surrounds  the 
spinal  cord.  It  differs  from  the  dura  mater  of  the  brain  in  that  it  does  not  form 
the  internal  periosteum  of  the  spinal  canal,  nor  the  fibrous  septa  fur  the  spinal 
cord  ;  it  does  not  contain  sinuses,  nor  adhere  to  the  walls  of  the  canal.  Like  the 
dura  mater  of  the  brain,  the  dura  mater  of  the  spinal  cord  sends  over  the  nerves 
tubular  prolongations  which  become  continuous  with  their  sheaths. 

The  periosteum  which  lines  the  spinal  canal  is  continuous  with  and  represents 
the  periosteal  layer  of  the  dura  mater  of  the  brain.  The  extra-dural  veins  of  the 
spinal  canal  (meningo-rachidian)  correspond  in  position  to  the  sinuses  of  the  dura 
mater  of  the  brain.  The  dura  mater  is  separated  from  the  walls  of  the  spinal 
canal  by  loose  areolar  tissue,  fat,  and  the  anterior  and  posterior  plexuses  of  the 
extra-dural  veins  (meningo-rachidian).  It  extends  from  the  lower  margin  of  the 
foramen  magnum  to  the  back  of  the  base  of  the  coccyx,  where  it  blends  with  the 
periosteum.  It  exists  as  an  enveloping  membrane  only  as  far  as  the  third  sacral 
vertebra,  beyond  which  it  is  impervious  and  exists  only  as  a  hollow,  slender  cord 
which  surrounds  the  filum  terminale.  It  is  attached  above  to  the  margin  of 


PLATE  CXIV. 


SPINAL  CORD  AND  MEMBRANES. 
429 


THK  SIVXAL   CORD.  431 

the  foramen  magnum,  to  the  axis,  and  third  cervical  vertebra;  and  below,  to  the 
posterior  surface  of  the  base  of  the  coccyx. 

DissKiTiox. — The  spinal  cord  and  its  membranes  should  now  be  removed. 
To  do  this,  divide  the  medulla,  oblongata  ami  membranes  of  the  cord  at  the  fora- 
men magnum,  and  the  spinal  nerves  as  far  outward  in  (lie  intervertebral  foramina 
as  possible,  so  as  to  preserve  the  ganglia  on  their  posterior  roots.  If  the  cord  be 
perfect  I  v  fresh,  it  should  be  hardened  before  its  membranes  are  removed  ;  but  if 
soft,  it  should  be  dissected  in  plenty  of  water,  which  will  protect  it  from  pulpefac- 
tion.  Incise  the  dura  mater  near  its  termination,  and  open  it  along  its  posterior 
median  surface  with  a  pair  of  blunt-pointed  scissors.  Care  must  be  taken  to  avoid 
injuring  the  subjacent  arachnoid.  Reflect  the  dura  mater  laterally,  and  note  the 
shining,  inner  surface.  Note  also  that  the  spinal  nerves  as  they  leave  the  cord  are 
enveloped  by  prolongations  of  the  dura  mater. 

It  will  be  seen  that  each  nerve  has  a  separate  tubular  prolongation  of  the 
dura  mater,  and  that  the  anterior  and  posterior  roots  of  the  nerves  are  separated 
by  a  septum.  The  space  exposed  by  reflecting  the  dura  mater  is  known  as  the 
subdural  space,  and  lies  between  the  dura  mater  and  the  arachnoid.  It  is  pro- 
longed for  a  short  distance  upon  the  roots  of  the  spinal  nerves. 

The  arachnoid. — The  arachnoid  is  a  thin,  delicate,  veil-like  membrane  which 
is  continuous  with  the  arachnoid  of  the  brain,  and  lies  between  the  dura  and  pia 
mater.  It  is  more  delicate  than  that  of  the  brain,  but  resembles  the  encephalic 
arachnoid  in  sending  tubular  prolongations  along  the  nerves.  It  is  attached  to 
the  dura  mater  behind  by  prolongations  of  connective  tissue.  These  trabeculae  of 
connective  tissue  are  not  always  demonstrable,  and  exist  only  in  few  and  scattered 
places.  Below  it  is  prolonged  upon  tJie  cauda  equina. 

It  will  be  noted  that  the  arachnoid  forms  a  long  sac,  the  cavity  of  which 
lies  between  the  arachnoid  and  the  pia  mater,  and  is  known  as  the  subarachnoid 
space.  It  contains  the  cerebro-spinal  fluid,  and  is  continuous  with  the  sub* 
arachnoid  space  of  the  brain.  To  demonstrate  this  space,  inflate  it  by  injecting 
air  into  it  through  a  blow-pipe  inserted  near  the  foramen  magnum.  This  will 
illustrate  the  condition  found  in  the  congenital  defect  spina  bifida,  in  which  there  is 
an  overabundance  of  cerebro-spinal  fluid  with  faulty  development  of  the  posterior 
wall  of  the  lumbar  portion  of  the  spinal  canal.  In  this  condition  the  membranes 
are  pushed  through  the  opening  in  the  spinal  canal  by  the  weight  of  the 
cerebro-spinal  fluid  which  occupies  the  space  now  containing  air. 

Through  the  foramen  magnum  the  subarachnoid  space  of  the  spinal  cord 
communicates  with  the  corresponding  space  of  the  brain,  and  through  openings  in 
the  posterior  part  of  the  fourth  ventricle  (foramina  of  Magendie,  Key,  and  Retzius) 
the  subarachnoid  space  of  the  brain  communicates  with  the  ventricles  of  the  latter 


432  SUUUK'AL   ANATOMY. 


Pressure  exerted  upon  (lie  swelling  of  a  spina  biiida  will  at  times  cause 
slight  bulging  of  the  anterior  fontanel.  As  the  suharachimid  space  eomnmni- 
eates  with  the  ventricles  of  the  brain,  opening  a  spina  bifida  may  drain  the  cerebro- 
spinal  thud  from  the  brain  and  result  in  fatal  convulsions. 

DISSECTION.  —  Incise  the  arachnoid  and  reflect  it  from  the  underlying  pia 
mater.  This  will  open  the  subarachnojd  space,  which  has  just  been  inflated.  It 
will  be  seen  that  the  arachnoid  is  attached  to  the  pia  mater  by  numerous  trahecuhe 
of  subarachnoid  tissue,  and  by  three  incomplete  septa,-  —  a  posterior  and  two  lateral, 
—  which  not  only  attach  the  two  membranes  to  each  other,  but  at  the  same  time 
divide  the  subarachnoid  space  into  compartments.  The  posterior  septum  is  placed 
opposite  the  posterior  median  fissure  of  the  cord,  and  is  less  marked  in  the  cervical 
region.  It  carries  blood-vessels  to  the  cord.  The  two  lateral  septa  are  formed  by 
the  ligamenta  denticulata. 

The  pia  mater.  —  The  pia  mater  is  a  thin,  delicate,  vascular  membrane  which 
is  continuous  with  the  pia  mater  of  the  brain.  It  is  closely  adherent  to  the  cord, 
and  sends  vertical  partitions,  or  septa,  into  the  anterior  and  posterior  median  fis- 
sures. Along  the  anterior  median  line  of  the  cord  the  pia  is  thickened  into  a 
glistening  band  —  the  Ihien  .<y*/n«/r//x.  The  pia  mater  is  supported  at  the  sides  by 
two  lateral  bands  —  the  ligamenta  denticulata.  Each  lii/niii/'iifnii/  denticulatum  is  a 
fibrous  band  which  is  attached  to  the  median  lateral  aspect  of  the  pia  from  the 
level  of  the  foramen  magnum  to  the  level  of  the  first  lumbar  vertebra.  The 
anachment  of  each  ligament  to  the  pia  is  found  midway  between  the  anterior  and 
posterior  nerve  roots.  From  this  attachment  each  ligament  extends  outward,  and 
is  attached  to  the  dura  mater  by  numerous  denticulations,  or  strips,  which  pass 
outward  in  the  interval  between  the  anterior  and  posterior  roots  of  the  spinal 
nerves.  These  processes  push  the  arachnoid  before  them.  It  will  be  seen  from  this 
arrangement  that  the  ligamenta  denticulata  divide  the  subarachnoid  space  into  two 
compartments,  in  the  anterior  of  which  the  anterior  roots  of  the  spinal  nerves  are 
found,  and  in  the  posterior  the  posterior  roots  of  the  nerves.  The  posterior  com- 
partment is  again  subdivided  by  a  third  or  posterior  septum,  already  mentioned  in 
connection  with  the  subarachnoid  space.  The  ligamenta  denticulata  swing  the 
cord  in  the  center  of  the  dural  sac.  From  the  conus  mednllaris  the  pia  mater  is 
continued  downward  as  a  slender  thread,  the  filwm  tcnuiiKiIr.  as  far  as  the  base  of 
the  coccyx,  to  the  periosteum  of  which  it  is  attached.  The  filum  terminale  con- 
tains very  little  nervous  matter,  and  is  distinguished  from  the  nerves  of  the  cauda 
equina  by  its  glistening  white  appearance. 

The  anterior  and  posterior  roots  of  the  spinal  nerves  emerge  from  the  antero- 
lateral  and  postero-lateral  aspects  of  the  cord,  and  form  a  double  row  on  each  side 
of  it.  The  anterior  roots  arise  from  the  anterior  horns  of  the  gray  matter  and  con- 


PLATE  CXV. 


Ligamentum  denticulatum 


Filum  terminale 


Dura  mater 
Anterior  spinal  a. 


I  S. 


Filurm  terminale 


28 


CAUDA  EQUINA. 
433 


Till-:  SPINAL   <'i >/.'!>.  i:;;, 

tain  motor  libers  ;  tin:  posterior  ;itv  sensory  tiliers,  and  arise  from  the  posterior 
horns.  The  liliers  of  the  anterior  root-  emerge  in  several  bundle-  \vhieh  are  not 
placed  in  a  single  line  :  whereas  the  po.-trrior  roots  are  larger,  and  their  iiliers  also 
emerge  in  several  bundles,  which  form  a  single  row  at  the  postero-lateral  fissure. 
These  roots  of  the  nerves  pass  along  lor  a  varying  distance  within  the  dttral 
-heath  of  the  cord,  which  intra-dnral  portion  of  their  course  is  called  intra-thecal. 
The  inti'ii-tlii'fiil  cnin-xi'  of  the  nerves  is  shorter  above  and  longer  below,  as  the 
upper  spinal  nerves  pass  transversely  outward  and  the  lower  pass  downward  with 
increasing  decrees  of  obliquity.  As  the  cord  terminates  opposite  the  second  lum- 
bar vertebra,  the  lumbar  and  sacral  nerves  and  the  coccygeal  nerve  have  a  longer 
intra-thecal  course  than  those  above.  If  the  lumbar  and  sacral  nerves  are  cut  out 
with  the  cord,  a  condition  similar  in  appearance  to  the  under  surface  of  a  horse's 
tail  will  be  seen,  and  hence  the  designation  cumin  r<juiu<i  given  to  these  nerves.  As 
the  spinal  cord  is  shorter  than  the  spinal  canal,  and  as  the  nerves  emerge  from  the 
whole  length  of  this  canal,  each  succeeding  nerve,  growing  longer  in  its  intra-thecal 
course,  is  held  to  the  cord  by  its  arachnoid  investment  until  opposite  its  foramen  of 
exit,  when  it  also  passes  horizontally  outward  like  the  first  spinal  nerve.  The  nerves 
of  the  catida  equina.  however,  pass  down  the  canal  parallel  to  one  another  and 
enter  the  intervertehral  foramina  a  little  obliquely.  The  two  roots  unite  within 
the  iutervertebral  foramen  to  form  a  single  nerve.  A  short  distance  above  the 
point  of  junction  the  posterior  roots  contain  swellings  or  ganglia.  These  ganglia 
contain  the  trophic  centers  for  the  sensory  fibers  of  the  spinal  nerves. 

The  Fissures  of  the  Spinal  Cord  are  an  anterior  median,  a  posterior  median, 
two  antero-lateral,  and  two  postero-lateral. 

The  anterior  median  is  a  true  fissure,  and  has  a  depth  equal  to  one-third  of 
the  antero-posterior  diameter  of  the  cord.  It  extends  the  entire  length  of  the  cord, 
and  is  the  continuation  of  the  corresponding  fissure  of  the  medulla  oblongata,  at 
the  lower  part  of  which  it  is  considerably  interrupted  by  the  decussation  of  the 
pyramids.  The  pia  mater  dips  into  it  as  a  double  fold. 

The  posterior  median  fissure  is  not  an  open  and  true  fissure,  but  a  narrow 
cleft,  lodging  only  a  process  of  the  pia  mater,  which  dips  into  it  and  forms  a  sep- 
tum. It  is  continuous  with  the  corresponding  fissure  of  the  medulla  oblongata,  and 
extends  in  depth  one-half  the  diameter  of  the  cord,  us  far  as  the  gray  commissure. 
With  the  anterior  median  fissure  it  divides  the  cord  into  two  symmetric  halves. 

An  antero-lateral  and  a  postero-lateral  fissure  or  groove  exist  on  each  side 
of  the  cord  at  the  lines  of  emergence  of  the  anterior  and  posterior  roots  of  the 
spinal  nerves.  The  antero-lateral  fissure  is  more  imaginary  than  real,  as  the  fibers 
of  the  anterior  roots  of  the  nerves  leave  the  cord  in  from  three  to  eight  thin 
bundles,  which  are  not  placed  in  a  single  row.  The  postero-lateral  fissure  is,  how- 


436  tl'RGICAL  ANATOMY. 

ever,  well  marked,  the  fibers  of  the  posterior  roots  of  the  nerves  emerging  from  it 
in  a  single  row  of  bundles.  It  is  deepest  in  the  cervical  region,  and  is  continuous 
with  the  dorso-lateral  iissure  of  the  medulla. 

Formerly,  the  spinal  cord  was  divided  into  three  columns, — an  anterior,  a 
lateral,  and  a  posterior, — which  are  marked  out  by  the  anterior  median,  antero- 
lateral,  postero-lateral,  and  posterior  median  fissures  ;  but  as  the  antero-lateral 
fissure  is  incomplete,  the  cord  is  now  divided  into  an  antero-lateral  and  a  posterior 
column. 

In  the  spinal  cord  the  arrangement  of  white  and  gray  matter  is  the  reverse  of 
that  in  the  brain,  its  white  matter  being  upon  the  outside  and  the  gray  matter 
inside,  though  the  gray  matter  comes  to  the  surface  at  the  bottom  of  the  posterior 
median  and  postero-lateral  fissures. 

The  Macroscopic  Structure  of  the  Spinal  Cord  in  a  transverse  section  is  very 
simple.  If  cut  across,  it  is  found  to  consist  of  white  matter  enveloping  an 
H-shaped  central  mass  of  gray  matter.  The  arms  of  the  H  are  in  the  form  of 
crescents  whose  convexities  are  adjacent  and  united  by  a  band  of  gray  matter 
called  the  gray  commissure,  a  misnomer,  however,  as  the  commissure  is  chiefly 
composed  of  decussating,  and  not  commissural,  fibers.  The  anterior  ends  of 
these  crescents  are  expanded  and  the  posterior  extremities  taper,  so  that  the 
crescents  have  been  described  as  comma-shaped.  The  portion  of  the  crescent  in 
front  of  the  commissure  is  called  the  anterior  horn,  while  that  part  behind  it 
is  termed  the  posterior  horn.  The  end  of  the  anterior  horn  is  rounded  and 
expanded  ;  the  posterior  horn  is  long  and  tapering,  gives  origin  to  the  posterior 
roots  of  the  spinal  nerves,  and  closely  approaches  the  surface  of  the  cord.  The 
anterior  horns  do  not  reach  the  surface,  but  send  out  numerous  nerve  fibers 
to  form  the  anterior  roots  of  the  spinal  nerves.  In  the  center  of  the  gray 
commissure  is  the  central  canal  of  the  cord,  which  is  lined  by  epithelium  and 
is  continuous,  above,  with  the  fourth  ventricle  of  the  brain.  It  appears,  upon 
section  of  the  cord,  as  a  very  small  spot.  This  canal  is  the  remains  of  the 
original  neural  canal  of  the  embryo,  from  the  walls  of  which  the  spinal  cord 
is  formed.  In  front  of  the  gray  commissure,  between  it  and  the  bottom  of 
the  anterior  median  fissure,  is  a  layer  of  white  substance  called  the  white 
commissure.  For  further  details,  both  as  to  arrangement  and  changes  in  size 
and  form  of  the  cord  on  section  at  different  levels,  the  reader  is  referred  to 
the  accompanying  illustrations. 

The  substantia  gelatinosa  Rolandi  is  a  translucent  mass  of  gray  matter 
which  caps  the  end  of  the  posterior  horn. 

It  has  been  demonstrated,  chiefly  through  embryologic  and  pathologic 
research,  that  the  bundles  of  medullated  nerve  fibers  in  the  white  matter  of  the 


PLATE  CXVI. 


C4. 


TI2. 


Co. 


SECTIONS  OF  SPINAL  CORD.    w.  R.  GOWERS. 
437 


PLATE  CXVI1. 


Anfero-foreraL 

J)rODVE. 


Anterior     infer/or  _J 
Pyramid     peduncle 
•0/tvjre/ body 


Anterior.    . 
Lonqifuaina/ 
F/ssure         Posterior 
Longirudinal 

Fissure. 

-Cerv/ca/ 
En/argemenl~ 


-Lumbar 
Enlargement 


-5ulcus 
/angiruainaiis 
mectius 
Middle 
Peduncle 
Superior 
Peduncle  of  rhe 

Cerebellum. 


ANTERIOR   VIEW 


POSTERIOR   VIEW. 


SPINAL  CORD. 
439 


PLATE  CXVIII. 


5en50ry  farts. 


G  Column  of  Goll.  II.  ColomD  Of  Bordaoh.  P. If.  Posterior  Horn.  A. 11.  Anterior  Horn.  D.C.  Direct  Cerebcllar  Tract. 
I'. I'.  Crossed  PyrainUlnl  Tnu'l.  I..H.H.  Lateral  (iroiiml  Hundle.  <:.T.  Cower-' Tract.  M.L.Z.  .Mixeil  Lateral  /.one. 
A  <:./:.  Anterior  Cround  HilniUc-.  !>.!'.  Direct  Pyramidal  Tract. 


NERVE-TRACTS  OF  SPINAL  CORD. 
441 


Till-:  SPINAL   CORD.  443 

spinal  con!  have  a  definite  arrangement.  Kach  half  of  the  spinal  cord  is  divided 
into  an  antcro-laleral  and  a  posterior  tract  l>y  the  postero-lateral  fissure. 

The  antero-lateral  tract  contains  the  direct  pyramidal,  crossed  pyramidal, 
and  direct  cerebellar  tracts,  (lowers'  tract,  and  the  antero-lateral  ground  bundle. 

That  portion  of  the  antero-lateraJ  tract  which  is  in  relation  with  the  anterior 
median  fissure  is  the  anterior  or  direct  pyramidal  tract  (column  of  Turck).  It 
is  the  continuation  of  the  anterior  pyramid  of  the  medulla,  and  contains  those 
fibers  which  do  not  decussate  in  the  medulla,  though  in  all  probability  they  do 
so  in  the  cord  by  passing  through  the  anterior  commissure  and  thence  to  the  crossed 
pyramidal  tract  of  the  opposite  side.  It  tapers  as  it  passes  downward,  and  termi- 
nates in  tin'  middle  of  the  thoracic  region.  It  contains  descending  fibers — i.  e., 
libers  in  which  nerve  impulses  descend. 

The  crossed  or  lateral  pyramidal  tract  contains  the  greater  number  of  the 
libel's  of  the  anterior  pyramid  of  the  medulla — those  which  decussate.  It  passes 
downward  into  the  posterior  portion  of  the  antero-lateral  tract  in  front  of  and  to 
the  outer  side  of  the  posterior  cornu.  It  contains  descending  fibers,  and  extends 
the  whole  length  of  the  cord. 

The  direct  cerebellar  tract  lies  between  the  lateral  pyramidal  tract  and  the 
surface  of  the  cord,  and  does  not  extend  further  forward  than  that  tract.  It  begins 
at  the  level  of  the  root  of  the  first  lumbar  nerve,  ascends  to  form  part  of  the  resti- 
form  body  of  the  medulla,  contains  ascending  fibers,  and  increases  in  size  as  it 
ascends. 

Gowers'  tract,  or  the  antero-lateral  ascending  tract,  is  a  band  of  fibers  on  the 
surface  of  the  cord  in  front  of  the  direct  cerebellar  tract.  It  contains  ascending 
fibers  which  enter  the  outer  side  of  the  tract  of  the  fillet. 

The  antero-lateral  ground  bundle  comprises  the  remainder  of  the  antero- 
lateral  tract.  This  has  been  subdivided  into  the  anterior  ground  bundle,  the 
mixed  lateral  zone,  and  the  lateral  ground  bundle. 

The  anterior  ground  bundle  is  separated  from  the  remainder  of  the  antero- 
lateral  ground  bundle  by  the  anterior  roots  of  the  spinal  nerves  and  the  anterior 
cornu.  This  division  is  hardly  warrantable,  as  it  contains  fillers  similar  to  those 
of  the  mixed  lateral  zone.  Its  fibers  connect  the  cells  of  the  anterior  cornu. 

The  mixed  lateral  zone  is  the  backward  continuation  of  the  anterior  ground 
bundle,  and  is  limited  behind  by  the  crossed  pyramidal  tract.  It  contains  both 
ascending  and  descending  fillers  which  are  connected  with  the  cells  of  the  anterior 
cornu.  The  anterior  ground  bundle  and  mixed  lateral  zone  seem  to  be  continuous 
above  with  the  posterior  longitudinal  bundle  of  the  medulla  oblongata. 

The  I//!/  ,-til  i/rttuiid  Imndle  lies  between  the  mixed  lateral  zone  and  crossed 
pyramidal  tract  externally,  and  the  crescent  of  gray  matter  internally.  Its  ante- 


444  SURGICAL   AXATOMY. 

rior  portion  contains  libers  which  arc  connected  with  the  anterior  cornu,  and  its 
posterior  portion  has  libers  connected  with  the  posterior  eoriiu. 

The  posterior  tract  of  the  white-  matter  of  the  cord  is  divided  into  two 
portions — the  columns  of  (loll  and  Bnrdach.  These  are  :-e  pa  rated  by  a  septum, 
and  on  the  surface  of  the  cord  by  a  furrow. 

The  column  of  Goll,  or  postero-internal  tract,  is  in  relation  with  the  posterior 
median  lissure.  It  contains  ascending  tibers  which  arc  derived  from  the  posterior 
roots  of  the  nerves  and  others  which  connect  the  cells  of  the  posterior  cornu. 

• 

Above,  it  is  continuous  with  the  posterior  pyramid  of  the  medulla. 

The  column  of  Burdach,  or  postero-external  tract,  lies  between  the  column 
of  Goll  and  the  posterior  cornu.  It  contains  ascending  libers  which  are  derived 
from  the  posterior  roots  of  the  nerves  and  others  which  are  associated  with  the 
cells  of  the  posterior  cornu.  Like  the  column  of  Goll,  it  is  continuous  above  with 
the  posterior  pyramid  of  the  medulla. 

The  boundary  zone  of  Lissauer  is  composed  of  the  most  external  fibers 
of  the  posterior  roots  of  the  spinal  nerves  ;  these  libers  ascending  in  that  column 
or  zone  to  enter  the  posterior  cornu. 

The  microscopic  structure  of  the  cord  is  not  within  the  scope  of  this  work, 
and  is  therefore  not  given. 

The  Arteries  of  the  Spinal  Cord  are  the  anterior  spinal  artery  and  the 
posterior  and  lateral  spinal  arteries  which  form  upon  the  cord  an  anterior  median 
and  four  postero-lateral  arteries. 

The  anterior  spinal  artery  is  a  small  branch  which  arises  from  the  vertebral 
artery  near  its  termination.  It  joins  its  fellow  of  the  opposite  side  in  front  of  the 
medulla  oblongata,  and  forms  a  single  median  vessel  which  descends  in  front  of 
the  cord  to  its  termination  and  for  some  distance  on  the  filum  terminate.  It  is 
joined  on  either  side  by  branches  from  the  lateral  spinal  arteries.  This  median 
vessel  is  lodged  under  the  pia  mater  in  the  anterior  median  fissure,  and  supplies 
the  cord  and  the  cauda  equina. 

The  posterior  spinal  arteries  are  derived  from  the  vertebral  artery  at  the  side 
of  the  medulla  ;  each  artery  passes  to  the  side  of  the  cord  and  divides  into  an 
anterior  and  a  posterior  branch,  one  branch  running  in  front  of  the  posterior  roots 
of  the  spinal  nerves  and  the  other  behind  them.  These  arteries  continue  down 
the  postero-lateral  aspect  of  the  cord  to  its  termination.  They  are  joined  by 
the  lateral  spinal  arteries  and  supply  the  adjacent  cord,  membranes,  and  cauda 
equina. 

The  lateral  spinal  arteries  in  the  cervical  region  are  branches  of  the 
vertebral,  ascending  cervical,  and  deep  cervical  arteries ;  in  the  thoracic  region,  of 
the  dorsal  branches  of  the  intercostal ;  and  in  the  lumbar  region,  of  the  lumbar 


7v//-;  *rr\AL  CORD. 

arteries.  They  enter  the  spinal  canal  through  the  intervertebral  foramina,  and 
divide  into  two  branches — one  of  which  goes  to  the  back  of  the  bodies  of  the 
vertebras  and  the  other  reaches  the  cord  upon  the  posterior  root  of  a  spinal  nerve. 
Some  of  the  latter  branches  join  the  anterior  median  artery  while  the  others  either 
terminate  in  the  nerve  root  or  join  the  postern-lateral  arteries  of  the  cord.  They 
supplv  the  cord,  its  membranes,  and  the  vertebra1. 

The  Veins  of  the  Spinal  Canal  and  Spinal  Cord  are  the  dorsi-spinal,  the 
meningo-rachidian,  the  vena;  basis  vertebra;,  and  the  veins  of  the  cord  itself. 
All  the  veins  of  the  spinal  canal  and  spinal  cord  are  devoid  of  valves. 

The  meningo-rachidian  veins  have  been  described. 

The  veins  of  the  spinal  cord  (medulli-spinal)  form  a  plexus  over  the  surface 
of  the  cord  within  the  pia  mater,  and  emerge  chiefly  from  the  anterior  and 
posterior  median  fissures.  Branches  from  the  plexus  pass  outward  upon  the  nerve 
roots  and  communicate  with  the  meningo-rachidian  veins  which  in  the  upper  part 
of  the  spinal  canal  empty  into  the  vertebral  and  the  inferior  cerebellar  veins  or 
into  the  inferior  petro.sal  sinuses,  and  in  the  lower  part  of  the  canal  into  the  inter- 
costal and  lumbar  veins. 

The  Motor,  Sensory,  and  Reflex  Areas  of  the  body  governed  by  the  spinal 
cord  at  different  levels  are  approximately  shown  in  the  accompanying  table 
from  Gowers.  While  it  is  not  my  object  to  go  into  any  details  as  to  the  structure 
or  function  of  the  spinal  cord,  it  is  perhaps  well  to  say  a  few  words  upon  the  sub- 
ject. Thus,  while  most  of  the  motor  fibers  cross  at  the  decussation  of  the  pyramids 
in  the  medulla,  the  sensory  fibers  cross  in  the  cord  throughout  its  entire  length. 
This  difference  in  the  motor  and  sensory  decussation  is  only  anatomic,  for  from 
the  functional  standpoint  they  cross  over  upon  the  same  principle — /.  e.,  practically 
upon  their  entrance  into  the  cord  :  the  motor  fibers,  with  the  exception  of  those 
of  the  direct  pyramidal  tract,  entering  above  en  masse,  soon  decussate  in  a  body ; 
and  the  sensory  fibers,  entering  at  different  levels,  cross  over  soon  after  their 
entrance,  thus  decussating  separately  all  along  the  cord. 

Reflex  Action  is  a  fanciful  designation  to  indicate  the  centripetal  impulse 
along  a  sensory  nerve  to  the  nerve  center  (gray  matter)  and  the  resulting 
centrifugal  (return,  reflected)  impulse  along  a  motor  nerve.  Thus,  if  a  corn  be 
stepped  upon,  the  resulting  excitation  of  the  gray  matter  of  the  cord  is  so  great 
that  it  promptly  responds  by  a  reflex  motor  impulse  tending  to  withdraw  the 
damaged  part  from  the  site  of  injury,  even  before  the  centripetal  impulse  reaches 
the  brain  and  the  individual  becomes  conscious  of  injury.  This  quick  reflex  act 
independent  of  conscious  action  is  what  is  generally  meant  by  reflex  action, 
though  all  acts  are  reflex. 

Each  portion  of  the  spinal  cord  from  which  a  pair  of  spinal  nerves  arise  is 


IK;  SURGICAL  AXATOVY. 

termed  M  Moment,  though,  of  course,  there  is  no  anatomic  separation  of  the  cord 
into  these  segments. 

Pathologic  processes  may  involve  one  of  these  segments  ;  sncli  a  lesion  is 
calldl  a  local  lesion  :  a  tumor  would  be  an  example  of  this.  When  one  or  more 
longitudinal  tracts  or  systems  of  iihers  are  diseased  the  condition  is  designated 
a  systemic  disease;  of  this,  loeomotor  ataxia  is  an  example. 

Disease  of  the  Spinal  Cord  may  all'ect  its  entire  transverse  area,  or  certain 
portions  of  it,  in  varying  lengths  ;  or  it  may  begin  at  any  level,  and  thence  extend 
upward  or  downward  ;  in  that  event  being  designated  ascending  or  descending. 

Inflammation  of  the  anterior  horns  of  the  spinal  cord  is  a  disease  quite  often 
seen  in  infants,  and  frequently  overlooked  ;  its  most  constant  symptom  is  paralysis 
of  a  group  of  muscles  of  the  extremities;  because  of  an  infant's  inability  to  walk, 
this  symptom  is  not  readily  detected. 

The  signs  of  lesions  of  the  cord  depend  upon  the  area  of  gray  matter  or 
column  of  nerve  fibers  involved.  Whether  the  symptoms  be  those  of  irritation  or 
of  paralysis  depends  upon  the  kind  and  degree  of  the  pathologic  process.  An 
active  congestion  of  the  cord  may  cause  symptoms  of  irritation,  such  as  tingling, 
iibrillary  twitching,  and  pains;  while  enough  turgescencc  and  exudate  to  cause 
marked  compression  will  result  in  numbness  and  motor  paralysis.  Passive 
congestions  produce  their  most  marked  symptoms  in  the  morning,  because  of  the 
gravitation  of  venous  blood  to  the  cord  during  recumbency  upon  the  back.  All 
active  inflammatory  diseases  of  the  spinal  cord  are  aggravated  by  exercise,  for  the 
double  reason  that  movements  of  the  spinal  column  and  functional  activity  of  the 
cord  increase  the  blood  supply.  Again,  an  intra-spinal  tumor  will,  as  it  begins  to 
encroach  upon  the  cord,  at  first  produce  signs  of  irritation,  and  compression 
symptoms  (paralysis  or  loss  of  function)  will  manifest  themselves  as  the  encroach- 
ment increases.  Any  disease  involving  the  integrity  of  the  entire  transverse 
diameter  of  the  cord  will  cause  complete  motor  and  sensory  paralysis  of  the  areas 
supplied  by  the  part  of  the  cord  at  and  below  the  site  of  the  disease.  If  the  lesion 
affect  only  one  lateral  half  of  the  cord,  there  will  be  motor  disturbance  on  the  same 
side  of  the  body  below  the  lesion  and  sensory  disturbance  upon  the  other  side, 
which  is  accounted  for  by  the  different  modes  of  decussation  of  the  motor  and 
sensory  nerve  fibers. 

No  other  affections  of  the  body  offer  the  same  field  for  absolute  accuracy  in 
diagnosis  and  localization  of  lesions  as  do  diseases  of  the  spinal  cord  ;  or,  in  fact, 
of  the  entire  cerebro-spinal  axis.  A  careful  study  of  the  areas  of  motor  and 
sensory  disturbance,  together  with  the  mode  of  onset  and  general  course  of  the 
disease,  usually  leaves  no  room  for  doubt  as  to  the  location  of  the  lesion,  though 
its  nature  mav  be  doubtful. 


PLATE  CX!X. 


Scapular 


Epigastric 


Abdominal 


Neck   and    Scalp 
Neck    and    Shoulder 

Shoulder 

Arm 

Hand 


Front  of  thorax 
Ensiform   area 


Cremasteric 
Knee-joint 

Gluteal 

Foot  clonus 
Plantar 


Abdomen 
(Umbilicus  loth) 


Buttock,   upper  part  • 
Groin   and   Scrotum   (front) 


outer  side 


front 


Thigh 


inner  side 

Leg,   inner  side 
Buttock,    lower   part 


Back   of   thigh  v 


except 
part 


Sterno-mastoid     )       «3 
Trapezius    , 

Diaphragm   -| 
/  Serratus     f 


/   berratus     f      ,  <T*\Y-  1_N  •? 

Should.,  {    j      6 ^V^f 

«.c.        Arm  1         7 -^\^ 


,  Hand 

(ulnar   lowest)    I    /  / 


Intercostal    muscles 


Abdominal   muscles 


Extensors,   knee 
Adductors 


Abductors 
Extensors  (?) 
Flexors,   knee   (?) 

Muscles  of  leg   moving 
foot 


inner    f    Leg   and    I 
t  \       toot       / 

Perineum   and   anus  /   '       Perineal   and   anal   muscles  •< 
nus  J 


Skin   from  coccyx  to  an 


(u 

Flexors,    hip     i 


APPROXIMATE  RELATION  TO  THE  SPINAL  NERVES  OF  THE  VARIOUS  MOTOR,  SENSORY,  AND  REFLEX  FUNCTIONS  OF 

THE  SPINAL  CORD  (COWERS). 
447 


rill.   SPINAL   CORD.  449 

Protection  to  the  Spinal  Cord  is  afforded  by  a  number  of  safeguards;  t 
an-  the  following  :  The  free  mobility  of  the  spinal  column  as  a  whole  ;  the  slight 
amount  of  movement  between  any  two  vertebra' ;  the  elastic  intervertebral  discs 
which  break  up  force  and  shock  applied  to  the  spinal  column;  the  comparatively 
large  size  of  the  spinal  canal  in  the  cervical  and  lumbar  regions  where  the  mobility 
is  most  marked  ;  the  curves  of  the  spinal  column  which  lessen  shock  and  force; 
suspension  of  the  cord  in  the  spinal  canal  by  the  ligamenta  denticulata  ;  the  spinal 
dura  mater  which  is  so  tough  that  the  cord  may  be  ruptured  without  laceration 
of  the  dura  ;  and  the  cerebro-spinal  fluid. 

Injuries. — The  spinal  cord  is  most  likely  to  be  injured  at  the  atlo-axoid 
joint,  at  the  junction  of  the  cervical  and  thoracic  regions,  and  near  the  junction  of 
the  thoracic  and  lumbar  regions  of  the  spinal  column.  At  the  atlo-axoid  joint 
injury  is  more  likely  because  of  the  mobility  of  that  part  of  the  spinal  column  and 
the  fact  that  in  that  location  the  cord  near!}-  fills  the  canal.  At  the  junction  of 
the  cervical  and  -thoracic  regions  injury  is  common,  because  there  the  freely 
movable  cervical  vertebra?  join  the  thoracic  vertebrae,  between  which  there  is  very 
little  motion.  Injury  of  the  cord  in  the  neighborhood  of  the  last  thoracic  and  first 
lumbar  vertebra  is  frequent,  because  in  that  location  the  almost  rigid  thoracic- 
region  joins  the  freely  movable  lumbar  region  of  the  spinal  column,  and  because 
the  length  of  that  part  of  the  spinal  column  above  permits  great  leverage. 

Fractures  of  the  Spinal  Column  are  usually  produced  by  indirect  violence, 
as  in  overflexion  or  overextension  of  the  spinal  column,  as  when  a  person  falls 
upon  the  head  or  buttocks,  or  is  stooping  and  a  heavy  weight  falls  upon  the 
shoulders,  one  of  the  supra-spinous  ligaments  ruptures  and  the  posterior  arches 
of  one  or  two  of  the  vertebrse  near  the  point  of  rupture  are  fractured.  Usually 
the  fragments  so  completely  crush  the  cord  that  operation  to  remove  or  elevate 
them  does  not  improve  the  condition. 

Fractures  of  the  spinal  column  above  the  fifth  cervical  vertebra — that  is, 
above  the  origins  of  the  phrenic  nerves — are  almost  invariably  fatal  because  of 
paralysis  of  the  diaphragm. 

Fractures  of  the  fifth,  sixth,  and  seventh  cervical  vertebrae  cause  paralysis 
of  the  intercostal  and  abdominal  muscles  ;  while  death  may  not  occur  at  an 
early  date,  respiration  can  only  be  maintained  by  the  action  of  the  diaphragm, 
and  this  finally  fails  through  lack  of  assistance  from  the  paralyzed  muscles. 

In  fractures  of  the  lower  part  of  the  thoracic  region  the  prognosis  is  not 
so  unfavorable. 

Tumors  within  the  spinal  canal,   arising  from  the  membranes  of  the   cord 
or  the  wall  of  the  canal,  as  they  increase  in  size,  gradually  cause  more  pressure 
upon  the  spinal  cord.     At  first,  through  irritation,  they  cause  spasm  and  hyper- 
20 


4.-.0  .  SURGICAL   ANATOMY. 

esthesia,  and  later,  through  pressure,  cause  complete  paralysis  and  anesthesia 
of  the  parts  supplied  l>y  the  portion  of  the  cord  below  the  site  of  the  Him<ir. 
There  may  be  some  disturbance  of  micturition  or  defecation,  but  after  a  time 
the  centers  in  the  spinal  cord  more  or  less  imperfectly  control  these  latter 
functions.  Irritation  of  the  cord  just  above  the  tumor  causes  a  girdle  sensa- 
tion, produced  by  the  nerves  which  arise  from  that  portion  of  the  cord.  In 
the  early  part  of  the  progress  of  the  growth  but  one  side  of  the  cord  is  usually 
affected  ;  later,  the  whole  cord  is  involved,  and  the  symptoms  are  present  in 
both  sides  of  the  body. 

.Marked  pressure  upon  or  any  other  total  transverse  lesion  of  the  spinal  cord, 
as  in  fractures  of  the  spinal  column,  irritates  the  nerves  which  arise  immediately 
above  the  lesion,  and  causes  pain  in  the  area  supplied  by  these  nerves.  There- 
fore girdle  pains  may  be  of  value  in  locating  the  lesion.  The  upper  thoracic 
nerves  supply  corresponding  intercostal  spaces ;  the  sixth  and  seventh  thoracic 
nerves,  the  region  of  the  ensiform  cartilage  ;  the  tenth  thoracic,  the  region  of  the 
umbilicus. 

Degeneration  in  the  Motor  Tracts  of  the  cord  descends,  and  in  the  sensory 
tracts  ascends.  This  is  due  to  the  fact  that  the  trophic  centers  of  the  motor  tracts 
are  in  the  gray  matter  of  the  brain,  whereas  those  of  the  sensory  tracts  are  in  the 
ganglia  upon  the  posterior  roots  of  the  spinal  nerves.  In  the  crossed  pyramidal 
tracts  we  find  three  sets  of  fibers — motor,  vasomotor,  and  fibers  which  carry 
impulses  for  inhibition  of  reflex  action.  The  vasomotor  and  inhibitory  fibers  pass 
to  the  motor  cells  of  the  anterior  horns.  When  the  crossed  pyramidal  tract 
degenerates,  these  inhibitory  and  vasomotor  fibers  are  included,  and  dilatation  of 
the  blood-vessels  and  increased  reflexes  result. 

Voluntary  motor  impulses  arise  in  the  motor  region  of  the  cerebral  cortex 
near  the  fissure  of  Rolando.  They  then  pass  through  fibers  of  the  corona  radiata, 
the  internal  capsule,  partly  through  the  corpus  striatum,  through  the  crusta  of  the 
crura  cerebri,  the  pons,  and  the  anterior  pyramids  of  the  medulla.  Here  most  of 
the  fibers  cross  to  enter  the  crossed  pyramidal  tract  of  the  opposite  side  of  the 
spinal  cord,  and  the  fibers  which  do  not  cross  continue  downward  as  the  direct 
pyramidal  tract  and  cross  through  the  anterior  or  white  commissure  to  the  anterior 
horn  of  the  opposite  side ;  therefore  all  impulses  eventually  pass  to  the  opposite 
side.  They  pass  to  the  motor  cells  in  the  anterior  horns  of  the  gray  matter,  and, 
through  the  motor  nerves  which  arise  from  these  cells,  pass  to  the  muscles. 

A  sensory  impulse  arises  in  the  sensory  end  organs  in  the  skin  and  passes 
along  the  sensory  nerves  directly  to  the  cells  in  the  posterior  horns,  or  indirectly 
through  the  column  of  Burdach  and  boundary  zone  of  Lissauer.  The  fibers 
pass  from  the  cells  in  the  posterior  horn  to .  the  postero-internal  column  of  the 


SURFACE  .\.\.\TOMY   OF   Till'.    CILIMI'M.  451 

opposite  side  and  the  direct  cerebellar  and  (.lowers'  tract  of  the  same  side.  These 
sensory  tihers  all  deeuss.-ite  in  the  cord  except  those  for  muscular  sense,  which 
decussate  in  the  medulla  oblongata.  Some  of  these  libers  pass  through  the 
posterior  pyramid  of  the  medulla  and  the  restiform  body  to  the  cerebellum,  and 
others  pass  through  the  formatio  reticularis  of  the  pons,  the  tegmentum  of  the 
crura,  the  optic  thalamus,  the  posterior  part  of  the  internal  capsule,  and  the 
corona  radiata  to  the  sensory  cells  of  the  gray  matter  of  the  cerebrum. 

As  some  of  the  motor  nerve-fibers  of  the  spinal  cord  cross  in  the  medulla 
oblongata  and  the  remainder  in  the  spinal  cord,  and  the  sensory  fibers  cross  in  the 
cord  soon  after  entering  it,  a  lesion  of  one-half  the  spinal  cord  causes  loss  of 
motion  and  hyperesthesia  of  the  corresponding  side  of  the  body  and  anesthesia 
of  the  opposite  side,  motion  on  this  side  not  being  much  affected. 

In  spinal  meningitis,  either  acute  or  due  to  caries  of  the  spinal  vertebrae, 
irritation  of  the  cord  causes  pain  along  the  course  of  the  spinal  nerves  and  spasm 
of  the  muscles  supplied  by  them. 


SURFACE  ANATOMY  OF  THE  CRANIUM. 

The  cranium  is  that  portion  of  the  head  which  extends  from  the  lower  margin 
of  the  forehead  in  front  to  the  upper  extremity  of  the  neck  behind,  from  ear  to 
ear  laterally,  and  along  the  base  of  the  brain-case  below.  The  base  of  the  brain- 
case  is  represented  by  a  line  which  extends  from  the  eyebrows,  through  the 
external  auditory  meatus,  to  the  nape  of  the  neck.  The  covering  of  this  area, 
with  the  exception  of  that  of  the  forehead  and  part  of  the  temporal  regions, 
constitutes  the  scalp. 

The  scalp  is  covered  by  hair,  which  is  more  or  less  abundant.  At  the 
junction  of  the  middle  and  posterior  thirds  of  the  sagittal  suture  can  be  seen  a 
dividing  point  of  the  hair,  from  which  it  falls  radially  in  all  directions.  It  is  at 
this  point  that  baldness  usually  begins.  The  density  of  the  scalp  is  well  marked. 
The  integument  is  closely  connected  with  the  cranial  or  occipito-frontalis 
aponeurosis,  on  account  of  which  attachment  many  persons  can  readily  move  the 
scalp  by  the  alternate  contractions  of  the  occipital  and  frontal  divisions  of  the 
muscle.  The  scalp  is  lacking  in  elasticity,  especially  in  the  back  part.  In  peeling 
the  scalp  back,  during  postmortem  examinations,  it  sometimes  tears,  and  in  the 
subsequent  sewing  stitches  pull  through  if  drawn  very  tightly.  In  this  respect 
the  scalp  differs  remarkably  from  the  skin  of  other  regions  of  the  body.  The  skin 
elsewhere  has  more  elasticity  and  allows  much  stretching  before  it  tears.  Tumors 


SURGICAL   AX  ATOMY. 

of  the  sculp  are  movable  if  above  the  cranial  aponeurosis  ;  when  below  it  they  are 
immovable. 

The  arteries  of  the  scalp  are  the  frontal,  which  ascends  near  the  median  line; 
the  supra-orbital,  which  is  found  above  the  supra-orbital  notch  and  for  some 
distance  up  the  forehead  ;  the  anterior  branch  of  the  temporal  artery  (often  very 
tortuous),  found  about  one  and  one-quarter  inches  behind  the  external  angular 
process  of  the  frontal  bone;  the  posterior  branch  of  the  temporal,  which  runs 
above  and  in  front  of  the  ear;  the  posterior  auricular,  above  and  behind  the  ear; 
and  the  occipital,  distinguishable  about  midway  between  the  mastoid  process  and 
the  external  occipital  protuberance. 

In  examining  the  head  as  a  whole,  it  will  be  noticed  that  the  two  sides  are 
not  symmetric — one  side  almost  always  having  larger  dimensions  than  the  other. 
Although  the  general  conformation  of  the  skull  cap  is  a  fair  index  of  its  contents, 
it  does  not  follow  that  every  minute  change  in  form  of  the  brain  has  its  effect  upon 
the  skull,  as  is  claimed  by  many  phrenologists. 

The  cranial  bones  are  the  frontal,  two  parietal,  two  temporal,  the  occipital, 
the  sphenoid,  and  the  ethmoid.  In  the  adult  they  are  immovably  connected  with 
one  another,  the  lines  of  their  junctions  being  termed  sutures.  In  infancy  the 
frontal  bone  consists  of  two  portions  ;  these  coalesce  very  early  in  life,  the  line  of 
union  being  the  frontal  suture.  The  two  parietal  bones  are  joined  by  the 
sagittal  suture.  The  course  of  the  two  sutures,  the  frontal  and  sagittal, 
corresponds  to  a  line  drawn  from  the  root  of  the  nose,  directly  backward  over  the 
median  line  of  the  vault  of  the  skull,  to  the  external  occipital  protuberance.  In 
this  line,  within  the  skull,  are  the  superior  longitudinal  sinus  and  the  longitudinal 
fissure  of  the  cerebrum.  The  parietal  bones  are  joined  to  the  frontal  bone  by  the 
coronal  suture,  and  to  the  occipital  bone  by  the  lambdoid  suture.  About  one  inch 
anterior  to  the  center  of  a  vertical  line  drawn  directly  over  the  skull  from  one  exter- 
nal auditory  meatus  to  the  other,  and  at  the  junction  of  the  coronal  with  the  sagittal 
suture,  is  the  bregma,  which  is  the  situation  of  the  anterior  fontanel  of  the  infant. 
The  coronal  suture  corresponds  to  a  line  drawn  from  the  bregma  to  the  middle  of 
the  zygomatic  arch.  The  lambdoid  suture  is  represented  by  a  line  drawn  from  the 
posterior  border  of  the  base  of  the  mastoid  process  to  a  point  midway  between  the 
bregma  and  the  external  occipital  protuberance.  The  lambda  is  the  point  of 
junction  of  the  sagittal  and  lambdoid  sutures.  This  is  the  site  of  the  posterior 
fontanel  in  infants.  The  pterion — the  junction  of  the  anterior  inferior  angle  of 
the  parietal,  the  frontal,  the  temporal,  and  the  greater  wing  of  the  sphenoid  bone 
— is  found  about  one  and  one-half  inches  behind  the  external  angular  process  of 
the  frontal  bone,  and  about  the  same  distance  above  the  zygoma. 

The  superciliary  ridges  commence  on  each  side  of  the  glabella,  which  is 


PLATE  CXX. 


jBregma 


Lower  level] 
of  Cerebrufn 


CRANIAL  LANDMARKS  AND   LINES  OF  CEREBRAL  FISSURES. 
453 


Sl'/tFACE  A. \ATOMY   OF   THE   CJUMI'M.  455 

the  elevation  above  the  root  of  the  nose,  and  extend  outward  in  a  gentle  curve, 
gradually  becoming  less  prominent.  The  superciliary  ridges  mark  tlic  location  of 
the  sinuses  of  the  frontal  hone,  but  may  vary  greatly,  generally  because  of  the 
difference  in  sixe  of  the  frontal  sinuses.  They  are  small  in  females  and  absent  in 
children.  Although  the  size  of  the  ridge  may  he  an  indication  of  the  size  of  the 
frontal  sinus,  yet  this  does  not  always  hold  good,  as  we  may  find  a  large  ridge  with 
but  little  development  of  the  sinus;  and  vice  versa.  Some  of  the  Australian  abor- 
igines have  very  small  sinuses,  but  large  ridges,  due  to  great  thickness  of  the  bone. 

Above  the  superciliary  ridges  are  found  the  frontal  eminences.  They  are 
slightly  convex  elevations  which  mark  the  original  centers  of  ossification  in  the 
two  frontal  bones.  Their  prominence  is  generally  considered  as  an  index  of  the 
amount  of  intellectual  capacity  of  the  individual.  The  increase  in  the  develop- 
ment of  the  skull  as  a  whole  causes  the  frontal  bones  to  become  upright,  and  thus 
makes  the  frontal  eminences  more  prominent. 

Immediately  behind  the  external  ear  is  the  mastoid  process  of  the  temporal 
bone.  It  is  but  rudimentary  in  infancy,  and  develops  later  in  life.  It  extends 
downward  for  about  an  inch  below  the  external  auditory  meatus,  and  projects 
forward  slightly  under  it.  The  digastric  fossa  is  internal  to  the  mastoid  process. 
The  body  of  the  process  is  honeycombed  with  air-cells,  which  are  connected  with  the 
middle  ear.  At  times  these  become  so  inflamed  that  trephining  or  incision  is 
necessary  to  afford  relief.  The  incision  should  be  made  in  the  hairless  space  behind 
the  car  (Wilde's  incision).  A  line  connecting  the  tips  of  the  two  mastoid  processes 
would  pass  through,  or  immediately  under,  the  condyles  of  the  occipital  bone. 

About  half  an  inch  above  and  three-quarters  of  an  inch  behind  the  posterior 
border  of  the  mastoid  process  is  the  asterion — the  junction  of  the  lambdoid  and 
squamous  sutures. 

The  external  occipital  protuberance  (inion)  is  distinctly  felt  in  the  median 
line  at  the  posterior  part  of  the  head,  at  the  junction  of  the  skin  of  the  neck  with 
that  of  the  head.  It  is  the  thickest  part  of  the  vault  of  the  skull.  From 
it  the  superior  curved  lines  of  the  occipital  bone  extend  laterally  and  give 
attachment  to  some  of  the  muscles  which  support '  the  head.  The  external 
occipital  protuberance  marks  the  position  of  the  torcular  Herophili,  or  the  con- 
fluence of  the  superior  longitudinal,  two  lateral,  straight,  and  occipital  sinuses. 
Above  the  superior  curved  lines  the  general  contour  of  the  skull  can  be  readily 
seen,  as  the  covering  is  composed  of  thin  structures.  Below  these  lines,  however, 
the  skull  recedes  to  a  considerable  extent,  the  space  being  filled  in  with  the 
strong  muscles  and  fasciae  of  the  neck.  In  the  region  of  the  occiput  there  is 
occasionally  found  a  bulging  of  the  membranes  of  the  brain  (meningocele),  or  of 
the  brain  itself  (encephalocele) ;  in  these  cases  there  is  defective  ossification  of  the 


156  SURGICAL   ANATOMY. 

occipital  bone,  and  tbo  tumor  caused  by  the  protruding  cranial  contents  is  always 
in  the  median  line. 

The  parietal  eminences  which  murk  the  position  of  the  centers  of  ossification 
in  the  parietal  bones  are  readilv  distinguishable  on  the  sides  of  the  skull  above  the 
ears.  They  are  much  more  marked  in  infancy,  gradually  becoming  rounded  and 
less  prominent.  Anterior  to  the  parietal  eminences,  and  running  along  the  sides  of 
the  head,  are  the  two  temporal  ridges  which  limit  the  temporal  fossa1  above  and 
give  attachment  to  the  temporal  fascia.  They  commence  at  the  external  angular 
process  of  the  frontal  bone  and  arch  upward,  backward,  and  then  downward,  to 
become  lost  on  the  posterior  roots  of  the  zygomatic  process.  The  point  where  the 
coronal  suture  is  crossed  by  the  temporal  ridge  is  known  as  the  stephanion.  It  is 
about  one  and  one-quarter  inches  above  the  pterion. 

The  middle  meningeal  artery  passes  upward  on  the  anterior  inferior  angle  of 
the  parietal  bone,  and  is  found  by  trephining  an  inch  and  a  half  behind  and 
about  an  inch  above  the  external  angular  process. 

The  course  of  the  superior  longitudinal  sinus  is  indicated  by  a  line  drawn 
over  the  median  line  of  the  top  of  the  head,  or  from  the  root  of  the  nose  to  the 
external  occipital  protuberance. 

The  course  of  the  horizontal  portion  of  the  lateral  sinus  is  shown  by  the 
posterior  part  of  a  line  drawn  from  the  external  occipital  protuberance  to  a  point 
one  inch  above  the  external  auditory  meatus.  The  sinus  turns  downward  and 
becomes  the  sigmoid  sinus  at  the  point  where  a  vertical  line  drawn  through  the 
posterior  border  of  the  base  of  the  mastoid  process  crosses  the  line  for  the  horizontal 
portion. 

The  course  of  the  sigmoid  sinus  is  marked  by  a  line  drawn  from  the  point 
of  termination  of  the  horizontal  portion  of  the  lateral  sinus  to  the  tip  of  the 
mastoid  process. 


SURFACE  ANATOMY  OF   THE  FACE. 

The  appearance  of  the  face  in  health  and  disease  deserves  attention  from  the 
physician.  In  infancy,  owing  to  greater  abundance  of  subcutaneous  fat  and  the 
lack  of  development  of  the  muscles  of  expression,  the  face  is  full  and  round  ;  the 
relatively  greater  development  of  the  brain  and  sense  organs  causes  the  upper 
portion  of  the  face  to  be  broader  than  the  lower  ;  the  nasal  fossa?  are  shallow,  and 
the  maxillary  bones  are  small. 

In  old  age  the  subcutaneous  fat  largely  disappears  and  the  integument 
becomes  wrinkled  and  thinner.  Not  infrequently  there  are  observed  areas  of 


SURFACE   ANATOMY   OF   THE  FACE.  -T>7 

thickened,  brownish  epidermis  (keratu.-is  i-enilis),  particularly  in  persons  much 
exposed  to  the  weather.  After  middle  life  there  is  a  tendency  to  dilatation  of  the 
superficial  vessels,  especially  on  the  nose  and  cheeks. 

The  absorption  of  the  alveolar  processes  and  loss  of  the  teeth  cause  the  charac- 
teristic appearance  of  the  mouth  in  old  age  ;  the  lips  being  inverted,  the  red  border 
becomes  narrower,  and  when  the  mouth  is  closed  the  chin  is  drawn  toward  the 
nose. 

The  more  or  less  characteristic  changes  produced  by  disease  can  not,  of  course, 
be  described  here;  allusion  may  be  made  to  the  waxy  line  of  the  skin  in  certain 
renal  affections,  the  cyanosis  in  grave  cardiac  lesions,  the  hectic  flush  associated 
with  pulmonary  tuberculosis,  and  the  "fades  hippocratica."  In  the  last  named 
the  sunken  temples  and  cheeks  ;  the  pointed  nose  and  chin  ;  the  dull,  leaden  hue  : 
tin  few  drops  of  perspiration,  and  the  cold,  clammy  skin  portend  the  near 
approach  of  death. 

The  supra-orbital  arches  are  readily  recognized  as  the  dividing  line  between 
the  forehead  and  the  face.  They  are  strong  arches  which  form  the  upper 
boundary  of  the  circumference  of  the  orbit.  They  are  covered  by  the  eyebrows. 
Internally  they  end  in  the  internal  angular  processes  of  the  frontal  bone,  which 
articulate  with  the  lacrymal  bone  and  the  nasal  process  of  the  superior  maxilla. 
Between  the  two  internal  angular  processes,  at  the  fronto-nasal  suture,  a  meningo- 
cele  or  an  encephalocele  sometimes  appears.  Externally,  the  supra-orbital  arches 
terminate  in  the  external  angular  processes,  which  articulate  with  the  malar  bone. 
Immediately  below  the  supra-orbital  arches  are  the  eyes.  They  and  their  lids 
present  points  of  interest.  In  size  the  eyes  do  not  vary  much  in  different  indi- 
viduals, the  apparent  difference  being  due  to  the  variations  in  the  length  of  the 
palpebral  fissure,  which  thus  permits  a  larger  or  smaller  portion  of  the  ocular 
surface  to  come  into  view.  The  palpebral  fissure  is  the  aperture  between  the 
edges  of  the  two  lids,  and  extends  from  the  inner  to  the  outer  canthus.  The  fissure 
is  not,  as  a  rule,  exactly  horizontal,  the  outer  canthus  being  generally  a  little 
higher  than  the  inner. 

By  everting  the  eyelids,  the  tarsal  cartilage  may  be  felt  as  a  thickened 
portion  of  the  lid.  The  vertical  arrangement  of  the  Meibomian  glands  in  the 
tarsal  cartilage  can  also  be  made  out.  During  sleep  the  eyeball  turns  upward  and 
inward,  thus  sheltering  the  pupil  behind  the  base  of  the  upper  lid  under  the  supra- 
orbital  arch,  the  lower  lid,  at  the  same  time,  moving  upward  and  somewhat 
inward.  In  fainting  spells,  or  during  sleep,  the  white  sclerotic  of  the  eyeball 
shows  through  the  palpebral  fissure.  This  fact  is  often  of  value  in  detecting  a 
sham  sleep  or  a  sham  faint ;  when,  after  gently  lifting  the  upper  lid  by  pressing 
upward  and  against  the  eyeball,  if  the  pupil  is  in  view,  the  patient  is  not  asleep. 


458  SURGICAL    .I.Y.I  TOMY. 

The  puncta  lachrymalia  arc  readily  discernible  near  the  inner  canthus,  the 
lower  being  the  larger  ami  more  c.xlcrnal.  The  introduction  nf  a  probe  into  the 
lacrynial  canaliculus  should  he  preceded  by  drawing  the  lid  outward,  thus 
straightening  the  canal. 

The  tendo  oculi  can  be  felt  after  drawing  the  eyelids  outward,  or  forcibly  clos- 
ing the  eye.  Immediately  behind  this  is  the  laerymal  sac.  If  a  knife  were  pushed 
backward  just  below  the  tendo  oculi  it  would  enter  the  sac,  with  the  angular 
artery  and  vein  on  the  inner  side  of  the  puncture.  A  probe  passing  through  this 
opening  into  the  sac,  and  then  downward,  slightly  outward,  and  backward,  would 
enter  the  nasal  duct  and  appear  in  the  inferior  meatus  of  the  nose.  Tension  upon 
the  tendon,  as  in  closure  of  the  eyelids,  compresses  the  sac,  with  which  it  is  closely 
connected,  thus  emptying  the  sac  and  forcing  the  tears  which  have  collected  at  the 
inner  angle  of  the  eye  down  the  nasal  duct. 

The  nasal  duct  extends  from  the  inner  angle  of  the  eye  to  the  inferior  nasal 
meatus,  just  under  the  inferior  turbinated  bone.  It  is  about  three-quarters  of  an 
inch  in  length,  and  constricted  in  its  middle.  The  lower  opening  in  the  nasal 
mucous  membrane  is  a  slit,  but  there  is  quite  a  large  opening  in  the  dry  bone. 
When  the  lower  end  of  the  duct  lies  in  the  lateral  wall  of  the  meatus  instead 
of  in  its  roof,  greater  difficulty  is  experienced  in  passing  a  probe  into  the  duct. 

The  lower  border  of  the  orbit  (infra-orbital  margin)  lies  immediately  below 
the  eyeball  and  is  formed  by  the  superior  maxillary  and  malar  bones.  It  can 
be  readily  felt  throughout  its  entire  extent. 

The  glabella  is  a  flat,  triangular  eminence  situated  between  the  two  internal 
extremities  of  the  superciliary  ridges.  Immediately  below  the  apex  of  the  glabella 
is  found  the  prominence  of  the  nose  formed  by  the  nasal  bones. 

The  form  of  the  nose  and  much  of  the  general  expression  of  the  face  are  due 
to  the  size  and  form  of  the  nasal  bones.  The  difference  in  these  bones  accounts  for 
the  variations  we  find  in  the  various  races.  In  the  Mongolian  and  Ethiopian  the 
nasal  bones  are  flat  and  broad  at  their  base,  and  thus  form  the  flat  nose  which  is 
so  characteristic  of  those  races.  In  the  Caucasian  race,  however,  the  nasal  bones 
are  narrow  and  elongated  as  well  as  prominent  at  the  bridge.  The  nose  is  rigid  at 
its  root  and  base  as  far  as  its  middle,  beyond  which  it  is  cartilaginous  and  flexible. 
The  intimate  adherence  of  the  skin  to  the  nasal  cartilages,  which  are  attached  to 
the  lower  ends  of  the  nasal  bones,  makes  furuncles  or  erysipelas  in  this  region 
exceedingly  painful,  because  of  the  lack  of  cutaneous  elasticity. 

The  lower  end  of  the  nose  is  open  and  divided  into  the  two  anterior  nares  by 
the  nasal  septum  and  the  columna.  It  should  not  be  forgotten  that  the  nose  is 
attached  lower  than  the  floor  of  its  cavity  ;  so  that  it  must  be  elevated  when  the 
interior  is  to  be  inspected. 


SURFACE  ANATOMY   OF  THE  FAt'K. 

Below  the  nose  is  seen  the  mouth,  which  is  the  upper  opening  of  the  gastro- 
intestinal tract.  The  lips  contain  muscles  and  vessels,  and  play  a  large  part  in  the 
general  expression  of  the  face.  In  the  living  suhject  the  pulsations  of  the  superior 
and  inferior  coronary  arteries  can  ho  easily  felt  by  holding  the  lips  between  the 
linger  and  the  thumb.  In  the  operation  for  harelip  these  arteries  are  divided, 
the  ensuing  hemorrhage  being  easily  controlled  by  pressure  with  the  finger  and 
thumb.  Although  the  aperture  between  the  lips  is  generally  spoken  of  as  the 
mouth,  it  must  be  remembered  that  the  mouth  extends  backward  from  the  lips  to 
the  pharynx. 

Below  the  lips  can  be  found  the  prominence  of  the  symphysis  of  the  lower 
jaw.  The  lower  jaw  is  easily  felt  from  the  symphysis  to  the  condyle,  where 
it  articulates  with  the  temporal  bone.  By  slight  pressure  along  the  bone 
the  alveolar  border,  in  which  the  teeth  are  set,  can  be  readily  distinguished.  In 
passing  the  finger  backward  along  the  lower  border  of  the  body  of  the  jaw  the 
angle,  which  is  at  the  junction  of  the  body  with  the  ramus,  can  be  distinguished. 
In  front  of  the  angle  is  a  depression  through  which  passes  the  facial  artery,  the 
pulsation  of  which  can  be  detected  in  the  living  subject.  The  condyle  of  the  lower 
jaw  is  felt  in  front  of  the  tragus  of  the  external  ear  and  below  the  zygomatic  arch. 
When  the  mouth  of  a  living  person  is  opened,  the  condyle  can  be  felt  leaving  the 
glenoid  fossa  and  advancing  upon  the  eminentia  articularis.  This  forward 
motion  of  the  condyle  affords  a  freer  access  to  the  external  ear,  which  can  be 
demonstrated  by  passing  the  little  finger  into  the  external  auditory  meatus  and 
opening  and  closing  the  mouth. 

In  the  supra-orbital  margin,  at  the  junction  of  its  inner  with  its  middle  third, 
is  the  supra-orbital  notch,  or  foramen,  which  gives  passage  to  the  supra-orbital 
vessels  and  nerve.  The  mental  foramen  is  found  in  the  lower  jaw,  opposite  the 
second  bicuspid  tooth  ;  it  gives  passage  to  the  mental  vessels  and  nerve.  In  a  line 
drawn  between  the  supra-orbital  notch  and  mental  foramen,  and  just  below  the 
infra-orbital  margin,  is  the  infra-orbital  foramen,  which  gives  passage  to  the  infra- 
orbital  vessels  and  nerve.  These  nerves  are  derived  from  the  fifth  cranial  nerve. 
Quite  frequently  accessory  foramina  are  found  external  to  the  constant  ones,  and 
usually  transmit  a  portion  of  the  nerve  which  commonly  passes  through  the 
normal  foramen.  These  anomalies,  especially  on  account  of  their  frequency,  are 
of  considerable  significance  in  the  treatment  of  neuralgias  by  nerve  section.  The 
anomalous  openings  occur  most  frequently  in  connection  with  the  supra-orbital,  the 
infra-orbital,  or  the  mental  foramen,  in  the  order  named,  and  upon  the  right  side. 
At  times  a  deep  groove  extends  for  several  inches  upward  from  the  accessory  supra- 
orbital  foramen  and  about  a  finger's  breadth  internal  to  the  temporal  ridge. 
Failure  to  obtain  relief  in  some  cases  of  neuralgia,  after  section  of  the  nerve  which 


460  SI'RGICAL  ANATOMY. 

passes  through  the  normal  foramen,  may  he  due  to  an  accessory  nerve,  instead  of 
to  central  disease  or  affections  of  the  ganglia  connected  with  the  parent  stem. 

Continuing  outward  from  the  external  angular  process  is  the  zygomatic  arch, 
formed  l.y  (lie  malar  hone  and  the  zygomatic  process  of  the  temporal  hone.  The 
anterior  part  of  the  arch  is  Hat  and  hroad,  and  forms  the  prominence  of  the  cheek, 
or  the  "cheek  bone."  Posteriorly,  the  zygomatic  arch  terminates  in  front  of,  and 
just  above,  the  external  auditory  meatus.  On  account  of  the  attachment  of  the 
dense  temporal  fascia  to  the  upper  border  of  this  arch,  the  lower  border  is  more 
easily  distinguished.  The  zygomatic  arch  forms  a  dividing  line  between  two 
depressions.  These  are  generally  filled  with  fat  in  the  healthy  individual,  and, 
therefore,  are  not  markedly  evident.  As  soon  as  a  wasting  disease  begins  to  tax 
the  organism,  the  fat  above  the  zygoma  is  absorbed,  and  this  bony  arch  becomes 
much  more  prominent;  as  the  wasting  progresses,  the  masseteric  depression  can  be 
plainly  seen,  and,  at  the  same  time,  the  fat  in  front  of  the  anterior  margin  of  the 
masseter  muscle  and  below  the  anterior  half  of  the  malar  bone  disappears,  with 
resultant  sinking  of  the  cheeks. 

The  arteries  of  the  face  are  the  temporal,  between  the  ear  and  zygoma,  and 
the  facial,  on  the  body  of  the  lower  jaw  just  in  front  of  the  masseter  muscle,  at  the 
angle  of  the  mouth,  and  passing  along  the  naso-labial  fold  and  side  of  the  nose  to 
the  inner  angle  of  the  eye.  The  facial  vein  runs  straight  across  the  face  from  the 
inner  canthus  of  the  eye  to  the  anterior  inferior  angle  of  the  masseter  muscle  at 
the  lower  border  of  the  lower  jaw.  The  anterior  temporal  and  facial  arteries  are 
useful  to  the  anesthetizer  in  studying  the  pulse,  and  also  to  the  physician  when 
the  patient  is  sleeping. 

Expression  is  due  to  muscular  traction  upon  the  facial  integument.  In  facial 
hemiplegia,  when  the  muscles  of  the  affected  side  have  lost  their  power,  expres- 
sion is  gone,  and  the  wrinkles  of  the  face  disappear.  The  "  expression  of  the  eye  " 
is  due  to  wrinkling  of  the  lids  and  the  peri-ocular  integument.  The  study  of  the 
relation  between  facial  expression  and  the  permanent  markings  of  the  face  resulting 
therefrom,  as  an  index  to  character  and  disposition,  is  still  in  its  infancy.  Note  the 
proximity  of  the  muscle  centers  of  the  face  in  the  ascending  frontal  and  parietal 
gyri  to  the  speech  center.  The  latter  is  at  the  tip  of  the  operculum  around  the 
ascending  arm  of  the  Sylvian  fissure,  and  at  the  lower  part  of  the  ascending  gyri. 
Just  above  it  is  the  lip  center,  followed  by  that  of  the  face,  fingers,  hand,  and  arm, 
with  that  of  the  lower  limb  overtopping  all.  Is  this  not  also  the  order  in  which 
these  muscle  groups  are  involved  during  increasing  animation  accompanying  a  dis- 
cussion ?  The  central  excitement  becomes  greater  and  extends  over  wider  areas, 
sending  larger  and  more  intense  impulses  to  those  muscle  bundles  which  traverse 
the  facial  integument  and  pull  its  surface  hither  and  thither,  forming  wrinkles, 


PLATE  CXXI. 


INCISIONS  FOR  DISSECTION. 
461 


Artery  in  superficial  fasci 


PLATE  CXXII. 


Superficial  fascia 


Occipito-frontalis  aponeurosis        ./Pericranium/        /         / 

Areolar  tissue^      Outer  table  of  skull      D.ploe 

LAYERS  OF  SCALP. 


)ura  mater 


CIRSOID  ANEURYSM. 
463 


SCALP.  Ki.-> 

dimples,  scowls,  and  puckerings,  expressive  of  the  condition  of  the  mind  in 
relation  to  the  nutter  engaging  it.  The  hahitnal  recurrence  of  these  emotional 
results  leaves  ii-  impress  hy  gradually  ondermining  the  elasticity  of  the  skin 
involved  and  hy  contracting  the  alleeted  muscles,  producing  upon  the  individual's 
face  indications  of  his  character  which  may  he  read  hy  all  who  are  competent. 

The  external  ear,  or  pinna,  is  placed  at  the  junction  of  the  face,  neck,  and 
cranial  vault.  The  general  conformation  and  direction  of  the  pinna,  and  its  utility 
for  the  collection  and  partial  condensation  of  sound,  need  only  he  mentioned. 
During  inspection  of  the  tympanic  memhrane  and  of  the  whole  length  of  the  exter- 
nal auditory  canal,  the  direction  of  the  latter  concerns  us  practically.  It  is  about 
an  inch  and  a  quarter  long.  When  removing  foreign  hodies,  which  frequently 
lodge  in  this  canal,  it  is  important  to  note  that  it  sags  at  its  outer  end,  and  can  he 
straightened  by  pulling  the  pinna  upward.  The  greatest  diameter  of  the  canal  is 
vertical  at  the  external  end,  and  transverse  at  the  internal.  The  upper  and 
posterior  portions  of  the  tympanic  memhrane  incline  outward. 


SCALP. 

DISSECTION. — The  dissection  of  the  scalp  should  be  made  before  that  of  the 
face  and  neck.  The  body  should  lie  on  its  back,  the  head  being  well  elevated  by 
means  of  a  large  block  placed  under  the  nape  of  the  neck.  The  head  having 
been  shaved,  an  incision  should  be  carried  from  the  root  of  the  nose  over  the 
middle  line  of  the  vertex  to  the  external  occipital  protuberance;  and  a  second 
incision,  at  a  right  angle  to  the  first,  commencing  at  the  nasal  eminence,  should 
extend  on  each  side  as  far  back  as  the  ear.  Beginning  at  the  junction  of  the 
two  incisions,  reflect  the  skin  backward  and  outward,  forming  two  flaps.  When 
dissecting  these  flaps  great  care  must  be  taken  to  remove  only  the  skin,  the  best 
guide  being  the  bulbs  of  the  hair,  which  are  in  the  superficial  fascia. 

The  scalp  is  that  portion  of  the  cranial  covering  which  lies  in  front  of  the 
superior  curved  ridges  of  the  occipital  bone  and  above  the  two  temporal  ridges, 
though  in  the  dissection  of  the  scalp,  for  convenience,  the  tissues  in  the  temporal 
region  are  included. 

Layers. — The  scalp  above  the  temporal  ridges  is  made  up  of  five  layers — viz., 
skin,  superficial  fascia,  occipito-frontalis  aponeurosis,  loose  areolar  tissue,  and  peri- 
cranium (external  periosteum).  In  the  frontal  and  occipital  regions,  in  place  of  the 
aponeurosis,  are  the  muscular  bellies  of  the  occipito-frontalis  muscle.  Below  the 
temporal  ridges  (in  the  temporal  regions)  the  scalp  is  composed  of  eight  layers — 

30 


SURGICAL   ANATOMY. 

viz.,  skin,  superficial  fascia,  attolens  and  attrahens  amvm  muscles,  occipito-fron- 
talis  (epicranial)  aponeurosis,  arcolar  tissue,  temporal  fascia,  the  temporal  muscle, 
and  the  periosteum.  That  which  is  usually  spoken  of  as  the  scalp  includes  the 
skin,  the  superficial  fascia,  and  the  OCClpito-frontalis  muscle  and  aponciirnsis  ;  these 
three  layers 'are  closely  adherent  to  one  another. 

The  skin  of  the  scalp  is  thicker  than  thai  of  any  other  part  of  the  body.  By 
means  of  the  superficial  fascia  the  skin  is  closely  adherent  to  the  oceipito-fronlalis 
muscle  and  aponeurosis,  which  accounts  for  the  movement  of  the  skin  with  the 
muscle  and  its  aponeurosis.  It  is  rich  in  sebaceous  glands  which,  when  enlarged 
on  account  of  occlusion  of  their  duds,  constitute  sebaceous  cysts  or  wens,  so 
common  in  this  region.  These  growths,  even  when  large,  except  in  very  rare 
instances,  are  superficial  to  the  oceipito-frontalis  aponenrosis,  and  with  care  can. 
therefore,  he  removed  without  risk  of  opening  the  areolar  tissue  layer.  The  skin  is 
well  nourished  by  the  vessels  of  the  .superficial  fascia. 

The  superficial  fascia  of  the  scalp  consists  of  but  one  layer,  which  presents  a 
granular  appearance,  due  to  the  nodulated  fat  and  dense  fibrous  septa.  Its  septa 
firmly  connect  the  skin  to  the  oceipito-frontalis  aponeurosis.  In  its  density  and 
capability  of  resisting  pressure  it  is  like  the  superficial  fascia  of  the  palm  of  the 
hand  and  sole  of  the  foot.  It  is  continuous  behind  with  the  superficial  fascia 
of  the  hack  of  the  neck  ;  laterally,  and  in  front,  with  the  superficial  fascia  of 
the  face.  It  contains  the  principal  blood-vessels  and  nerves  of  the  scalp,  in 
this  respect  differing  from  the  superficial  fascia  elsewhere,  with  the  exception 
of  that  of  the  face  and  ischio-rectal  fossa?,  the  muscles  of  the  auricle,  and  the 
hair-bulbs.  The  arteries  of  the  scalp  lie,  as  it  were,  in  canals  in  the  fascia, 
and  are  attached  to  the  walls  of  these  canals  by  loose  fibrous  tissue;  when 
divided,  they  have  a  slight  tendency  to  retract  within  these  channels  or  canals, 
and,  on  account  of  the  density  of  the  fascia,  it  may  he  difficult  to  seize 
them  with  the  artery  forceps.  Consequently,  some  form  of  pressure1  is  often 
employed  to  check  the  bleeding.  The  presence  of  the  hair-bulbs  in  this 
dense  fascia  and  their  firm  attachment  to  the  scalp  enable  a  strong  person, 
by  securely  grasping  the  hair,  to  lift  the  entire  weight  of  the  body  without  tear- 
ing out  the  hair-roots.  Owing  to  the  density  of  the  superficial  fascia,  redness 
and  swelling  are  not  very  pronounced  in  inflammation  of  the  scalp.  The  super- 
ficial fascia  is  thickest  in  the  occipital  region,  and  gradually  grows  thinner  as  it 
approaches  the  front  and  sides  of  the  cranium. 

Wounds  of  the  scalp  bleed  freely,  because  the  arteries  can  not  contract  or 
retract  on  account  of  the  density  of  the  superficial  fascia  and  their  close  adherence 
to  the  connective-tissue  septa  within  which  they  ramify. 

DISSICCTIOX. — Upon  one  side  of  the  head  the  superficial  fascia  with  the  vessels 


PLATE  CXXIII. 


Ante  •  al  a. 


Supraorbital  a. 
Frontal  a. 


Posterior  temporal  a. 


• 

C/- 


•'    . 

• 

. 


1 


1 

I 


Posterior  auricular  a. 


Occip 


SUPERFICIAL  FASCIA  OF  SCALP, 
467 


and  nerves  are  i<>  be  removed  a.-  one  common  layer,  bringing  into  view  the  corre- 
sponding half  of  the  occipito-frontalis  aponeurosis  and  muscle;  while  upon  tin- 
other  side  only  the  superficial  fascia  in  the  immediate  neighborhood  of  the  vessels 
and  nerves  is  to  lie  removed,  in  this  way  exposing  and  giving  a  clear  idea  of  the 
blood  and  nerve  supply  of  the  scalp.  In  reflecting  the  superficial  fascia  preserve 
the  attolens  and  attrahens  aurem  muscles  which  lie  between  it  and  the  aponeurosis. 

The  Extrinsic  Muscles  of  the  Ear  are  very  feeble  and  rudimentary,  the 
auricle  in  man  being  practically  immovable.  They  are  three  in  number — the 
attolens  aurem,  attrahens  aurem,  and  retrahens  aurem  ;  they  require  con>iderable 
care  in  dissection  to  avoid  being  overlooked  and  destroyed. 

DISSECTION. — Draw  the  pinna  downward  and  fasten  it  with  hooks;  this  will 
make  tense  the  attolens  and  attrahens  aurem  muscles. 

The  attolens  aurem,  the  largest  of  the  three  muscles,  is  broad  and  fan-shaped, 
converging  to  a  narrow  tendon  below.  It  arises  from  the  superficial  surface  of  the 
occipito-frontalis  aponeurosis  below  the  temporal  ridge,  and  is  inserted  into  the 
cranial  aspect  of  the  upper  part  of  the  pinna. 

NKKVI;  SKI-PLY. — From  the  temporal  branch  of  the  facial  nerve. 

ACTION. — It  draws  the  pinna  upward. 

The  attrahens  aurem  is  the  smallest  muscle  of  the  three,  and  arises  from 
the  occipito-frontalis  aponeurosis  in  front  of  the  attolens  aurem  muscle,  and  is 
inserted  into  the  front  of  the  helix. 

NI:I;VI:  STPPLY. — From  the  temporal  branch  of  the  facial  nerve. 

ACTION. — It  draws  the  pinna  forward  and  upward. 

DISSECTION. — Release  the  pinna  from  its  present  position  and  draw  it  forward  ; 
fasten  it  with  hooks,  and  divide  the  integument  over  the  tense  band  behind  the 
auricle  to  expose  the  retrahens  aurem  muscle. 

The  retrahens  aurem  muscle  consists  of  two  or  three  short  muscular  bundles 
which  arise  from  the  mastoid  process  of  the  temporal  bone  and  are  inserted 
into  the  back  of  the  concha. 

NERVE  Srppi.Y. — From  the  posterior  auricular  branch  of  the  facial  nerve. 

ACTION. — It  draws  the  pinna  backward. 

The  Arteries  of  the  Scalp  are  derived,  in  front,  from  the  supra-orbital  and 
frontal  arteries ;  on  the  sides,  from  the  temporal  ;  and  behind,  from  the  posterior 
auricular  and  occipital  arteries. 

The  supra-orbital  artery,  a  branch  of  the  ophthalmic,  leaves  the  orbit 
through  the  supra-orbital  notch,  and  divides  into  a  superficial  and  a  deep  branch, 
which  ascend  toward  the  vertex,  anastomosing  with  the  temporal  and  frontal  arte- 
ries and  with  the  supra-orbital' artery  of  the  opposite  side.  It  supplies  the  tissues 
of  the  forehead. 


470  SURGICAL   A \ ATOMY. 

The  frontal  artery,  one  of  the  two  terminal  branches  of  the  ophthalmic, 
leaves  the  orbit  at  its  inner  angle  and  ascends  on  the  forehead,  anastomosing  with 
the  supra-orbital  and  with  the  frontal  artery  of  the  opposite  side. 

The  temporal  artery,  the  smaller  of  the  two  terminal  divisions  of  the  exter- 
nal carotid,  commences  in  the  substance  of  the  parotid  inland  and  ascends  over  the 
posterior  root  of  the  zygoma,  about  two  inches  above  which  it  divides  into  the 
anterior  and  posterior  temporal ;  in  some  cases  it  divides  immediately  after  crossing 
the  zygoma  ;  rarely,  it  divides  below  the  zygoma.  It  is  accompanied  by  branches 
of  the  facial  and  auriculo-temporal  nerves.  It  is  covered  by  the  attrahens  aurem 
muscle  and  crossed  by  one  or  two  small  veins.  The  temporal  and  anterior 
temporal  arteries  are  the  vessels  used  by  the  anesthetize!'  to  ascertain  the  character 
of  the  pulse. 

The  (interior  temporal  artery  passes  forward  in  a  tortuous  course  to  anas- 
tomose with  the  supra-orbital  and  frontal  arteries  and  with  the  anterior  temporal 
artery  of  the  opposite  side'.  It  supplies  the  tissues  along  its  course.  It  is  the 
branch  usually  selected  when  blood  is  to  Lie  extracted  from  the  arterial  system. 

The  /toalerior  temporal  artery,  the  larger  of  the  two,  passes  upward  and 
backward  above  the  pinna  and  anastomoses  with  the  posterior  temporal  artery 
of  the  opposite  side  and  with  the  occipital  and  posterior  auricular  arteries. 

The  transverse  facial,  anterior  auricular,  and  middle  temporal  branches  of  the 
temporal  artery  will  be  described  with  the  dissection  of  the  face. 

The  posterior  <iuririil<ir  (irfert/  passes  over  the  mastoid  process,  and  divides  into 
two  branches — an  anterior  and  a  posterior.  The  anterior  branch  passes  forward 
and  anastomoses  with  the  posterior  temporal  artery;  the  posterior  branch  passes 
backward  and  anastomoses  with  the  occipital  artery.  It  is  accompanied  by  the 
posterior  auricular  nerve,  a  branch  of  the  facial  nerve. 

The  occipital  artery  pierces  the  trapezius  muscle  at  its  attachment  to  the 
superior  curved  line  of  the  occipital  bone,  about  midway  between  the  mastoid 
process  and  the  external  occipital  protuberance.  Thence  it  ascends  in  a  tortuous 
course  over  the  back  of  the  head  to  the  vertex,  dividing  into  numerous  branches, 
which  anastomose  with  the  occipital  artery  of  the  opposite  side  and  with  the  pos- 
terior temporal  and  posterior  auricular  arteries.  It  is  accompanied  by  the  great 
occipital  nerve. 

The  arteries  of  the  scalp  sometimes  become  elongated  and  tortuous,  producing 
what  is  known  as  cirsoid  aneurysm.  The  anterior  temporal  artery  is  the  one  most 
commonly  affected. 

The  Veins  of  the  Scalp  accompany  the  corresponding  arteries,  with  the 
exception  of  the  supra-orbital  and  frontal  veins,  which  unite  to  form  the  angular, 
the  commencement  of  the  facial,  vein.  The  veins  of  the  scalp  communicate  with 


PLATE  CXXIV. 


Supraorbital  a 
Frontal  a. 


Orbital  a. 

niporal  a. 
Posterior  temporal  a. 


Occipital  a. 


Posterior  auricular  a. 


Angular  a. 


Facial  a. 

Inferior  Labial  a. 
Inferior  coronary  a. 
Superior  coronary  a. 


Superficial  temporal  a. 

\ 

Anterior  auricular  a. 

Middle  temporal  a. 
Parotid  gland 
Transverse  facial  a. 
Stenson's  duct 


ARTERIES  OF  SCALP  AND  FACE 
472 


PLATE  CXXV. 


Temporal  br.  of  orbital  n. 
Supraorbital  n. 
Supratrochlear  n. 


Malar  br.  of  facial  n. 


Temporal  br.  of  facial  n. 


i 

.  A  i\\- 


Great  occipital  n. 
Small  occipital  n. 


Auriculo-temporal  n. 
Infraorbital  br.  of  facial  n. 
v 

Great  auricular  n. 


'Supramaxillary  br.  of  facial  n. 
Buccal  br.  of  facial  n. 


Mental  n. 
Infratrochlear  n 


Infraorbital  br.  of  superior  maxillary  n. 

• 


Nasal  n. 


NERVES  OF  SCALP  AND  FACIAL  NERVE. 
473 


I  LI'.  47.'> 

the  sinuses  in  the  interior  of  the  skull  and  with  the  veins  of  the  diploi-  l>y  menus 
of  till'  emissary  veins. 

The  Nerves  of  the  Scalp  are  branches  of  the  trifaciul,  facial,  and  great  occip- 
ital nerves,  and  of  the  cervical  plexus. 

The  supra-orbital  nerve,  the  larger  of  the  two  terminal  branches  of  the  frontal 
branch  of  the  ophthalmic  nerve,  leaves  the  orbit  with  the  supra-orbital  artery 
through  the  supra-orbital  notch  or  foramen,  which  is  located  in  the  upper  margin 
of  the  orbit  at  the  junction  of  its  inner  and  middle  thirds,  and  ascends  upon  the 
forehead  beneath  the  orbicularis  palpebrarum  and  the  frontal  belly  of  the  occipito- 
t'rontalis  muscle.  It  divides  into  two  branches — an  inner  and  an  outer — and 
liecoines  subcutaneous;  the  inner  brand),  the  smaller,  pierces  the  frontal  belly  of 
the  occijiito-frontalis  muscle  and  ascends  as  high  as  the  parietal  bone  ;  the  outer 
branch,  the  larger,  pierces  the  occipito-frontalis  aponeurosis  and  ascends  over  the 
vertex  as  far  as  the  occipital  bone. 

The  supra-trochlear  nerve,  the  smaller  of  the  two  terminal  brandies  of  the 
frontal  branch  of  the  ophthalmic  nerve,  appears  at  the  inner  angle  of  the  orbit 
above  the  pulley  of  the  superior  oblique  muscle,  and  ascends  upon  the  forehead. 
It  is  covered  by  the  orbicularis  palpebrarum  and  frontalis  muscles,  piercing  the 
latter  to  end  in  the  integument.  It  supplies  the  skin  of  the  forehead  and  the 
upper  eyelid. 

Neurectomy. — The  supra-orbital  and  supra-trochlear  nerves  are  often  nilected 
by  neuralgia,  for  the  relief  of  which  division  or  resection  of  these  nerves  may  be 
required.  The  supra-orbital  notch,  if  present,  forms  a  sure  guide  to  the  position 
of  the  supra-orbital  nerve,  which  can  be  reached  and  exposed  by  a  vertical  incision 
immediately  over  the  notch,  or  by  a  transverse  incision  parallel  to  and  a  little 
below  the  eyebrow.  The  latter  method,  as  it  leaves  a  less  noticeable  scar,  is  the 
one  more  commonly  practised.  The  former  method,  however,  will  expose  a  larger 
portion  of  the  nerve.  The  skin  having  been  divided  by  either  a  vertical  or  a 
transverse  incision,  the  further  dissection  should  be  in  a  direction  parallel  to  the 
fibers  of  the  orbicularis  palpebrarum  muscle.  The  old  subcutaneous  operation  is 
now  seldom  done  on  account  of  the  extensive  extravasation  from  division  of  the 
supra-orbital  vessels.  To  divide  the  nerve  well  back  in  the  orbit,  it  is  necessary  to 
sever  the  orbito-tarsal  ligament  and  depress  the  orbital  fat,  when  the  nerve  is  sepa- 
rated from  its  connections  and  lifted  on  a  blunt  hook.  The  supra-trochlear  nerve 
is  exposed  through  an  incision  carried  in  a  line  drawn  from  the  angle  of  the  mouth 
through  and  beyond  the  inner  canthus.  The  nerve  will  be  found  at  the  point 
of  intersection  of  this  line  with  the  upper  margin  of  the  orbit.  The  occasional 
presence  of  an  accessory  supra-orbital  foramen,  giving  passage  to  a  division 
of  the  supra-orbital  nerve,  should  not  be  overlooked.  Recurrence  of  pain 


176  SURGICAL   ANATOMY. 

immediately  after  operation  is  good  presumptive  evidence  of  the  existence  of 
mi  accessory  foramen. 

Temporal  branch  of  the  orbital  nerve. — About  an  inch  a  hove  the  zygoma 
the  temporal  i'ascia  is  ]iierced  by  tlie  temporal  liraneli  of  the  orbital  branch  of  the 
superior  maxillary  nerve,  which  is  distributed  to  the  integument  of  the  temple 
and  communicates  with  the  temporal  branch  of  the  facial  nerve. 

The  auriculo-temporal  nerve,  a  branch  of  the  inferior  maxillary  nerve. 
accompanies  the  temporal  vessels,  lying  posterior  to  them.  The  auriculo-temporal 
nerve  emerges  from  beneath  the  upper  part  of  the  parotid  gland,  and  divides  into 
two  terminal  branches — the  anterior  and  posterior  temporal.  The  anterior 
temporal  nerve,  the  larger,  accompanies  the  anterior  temporal  artery  to  the 
vertex,  and  communicates  with  the  facial  and  temporo-malar  nerves.  The 
posterior  temporal  nerve,  the  smaller,  accompanies  the  posterior  temporal  artery. 

Temporal  branches  of  the  facial  nerve  extend  upward  over  the  zygoma  upon 
the  temple  to  supply  the  attrahens  and  attolens  aurem,  the  orbicularis  palpe- 
brarum,  the  frontalis,  and  the  c-orrugator  supercilii  muscle.  They  communicate 
with  tlie  temporo-malar,  auriculo-temporal,  lacrymal,  and  supra-orbital  nerves. 

The  posterior  auricular  nerve,  a  branch  of  the  facial,  accompanies  the 
posterior  auricular  artery,  and,  like  the  latter,  divides  into  two  branches — a 
posterior  and  an  anterior.  The  posterior  (occipital)  supplies  the  occipitalis  muscle  : 
the  anterior  (auricular),  the  auricle  and  the  retrahens  and  attolens  aurem  muscles. 
This  nerve  is  joined  by  filaments  from  the  auricular  branch  of  the  pneuniogasirie 
nerve  and  from  the  great  auricular  and  small  occipital  nerves. 

The  small  occipital  nerve  (occipitalis  minor),  a  branch  of  the  anterior  division 
of  the  second  cervical  nerve,  supplies  the  scalp  behind  the  ear  and  over  the  occiput. 
It  communicates  with  the  great  auricular  and  the  great  occipital  nerve,  and  with 
the  posterior  auricular  branch  of  the  facial  nerve.  It  can  be  seen  in  the  neck 
running  along  the  posterior  border  of  the  stemo-mastoid  muscle. 

The  great  occipital  nerve  (occipitalis  major),  the  largest  cutaneous  nerve  of 
the  scalp,  accompanies  the  occipital  artery  over  the  occiput.  It  is  the  internal 
branch  of  the  posterior  division  of  the  second  cervical  nerve;  pierces  the  corn- 
plexus  and  trapezius  muscles  near  their  attachment  to  the  occipital  bone  ;  enters 
the  superficial  fascia  with  the  occipital  artery,  and  breaks  up  into  a  number  of 
large  branches  which  spread  over  the  back  of  the  head,  supplying  the  integument 
as' far  forward  as  the  vertex.  It  communicates  with  the  small  occipital  and  the 
first  cervical  nerve,  and  receives  a  branch  from  the  third  cervical  nerve. 

The  Lymphatics  of  the  Scalp  follow  the  same  course  as  the  blood-vessels, 
which  is  the  general  rule.  The  posterior,  or  occipital,  lymphatics  enter  the 
occipital  glands  situated  along  the  origin  of  the  occipitalis  muscle ;  the  postero- 


PLATE  CXXVI. 


•r.  of  faciaM  n.     Iran.  , 


Orbital  a.  Temporal  br. of  facial  n. 


Temporal  br.  of  o   • 
Supra' 
S  u  p  r  i 

Supratroc; 

Frontal  a 
Angular  a. 

I 


Posterior  temporal  a. 
Auriculo-temporal  n. 
Superfical  temporal  v, 


Occipital  a. 


Great  occipital  n. 


Small  occipital  n. 


Posterior  auricular  a. 


Superior  coronary  a) 

Inferior  coronary  a 

Infer ior  labial  a 

Facial  a 

Fi 


Anterior  auricular  a. 
Middle  temporal  a. 
Parotid  gland 

Supramaxillary  br.  of  facial  n. 
Stenson's  duct 


Buccal  br.of  facial  n. 
Infraorbital  br.of  facial  n, 
Socia  parottdis 


ARTERIES,  NERVES,  AND  MUSCLES  OF  SCALP  AND  FACE, 
477 


M  'ALP.  17'.) 

> 

lateral,  or  posterior  auricular,  set  enter  (he  posterior  auricular  glands  situated  upon 
(he  niastoid  attachiucnt  of  the  sternomastoid  niusele  ;  the  temporal  lyuiphalics 
enter  the  glands  situated  upon  and  within  (lie  parotid  gland;  and  a  frontal 
set  end  in  (he  facial  lymphatics.  In  congestion  of  the  scalp  due  to  cold,  and  in 
other  atfectioiis  of  this  region  which  increase  the  activity  of  the  lymphatics,  these 
glands  are  considerably  swollen  and  painful. 

The  occipito-frontalis  muscle  and  aponcurosis,  exposed  upon  the  side  from 
which  the  superficial  fascia  has  been  removed,  will  now  he  studied. 

The  occipito-frontalis  is  a  broad,  musculo-aponeurotic  layer  covering  one  side 
of  the  vertex  of  the  skull  from  the  occiput  to  (he  brow.  It  consists  of  two 
flattened  muscular  bellies,  an  occipital  and  a  frontal,  with  an  intervening  aponeu- 
rosis. 

The  ncci/iifii!  />i'/li/  (nirijiitfi/ix  munch'),  thin  and  quadrangular,  arises  from  the 
outer  two-thirds  of  the  superior  curved  ridge  of  the  occipital  bone  and  the 
adjoining  niastoid  process,  thus  leaving  a  triangular  interval  between  the  two 
occipitales  muscles  as  their  fibers  eventually  meet  higher  up  in  the  median 
line.  The  fibers  are  about  an  inch  and  a  half  in  length  and  ascend  to  the 
aponeurosis. 

BLOOD  SUPPLY. — From  the  occipital  and  posterior  auricular  arteries. 

XKKVK  SUPPLY. — -The  occipitalis  muscle  derives  its  nerve  supply  from  the 
posterior  auricular  branch  of  the  facial  and,  exceptionally,  from  the  occipitalis 
minor  nerve. 

The  fntiital  belly  (frontalis  muscle),  a  thin,  muscular  layer  having  intimate 
cutaneous  connections,  arises  from  the  aponeurosis  below  the  coronal  suture.  It 
descends  over  the  forehead  and  blends  with  the  orbicularis  palpebrarum,  the  corru- 
gator  supercilii,  and  the  pyramidalis  nasi  muscle. 

BLOOD  SUPPLY. — From  the  frontal,  supra-orbital,  and  anterior  temporal  arteries. 

NKKVE  SUPPLY. — The  frontalis  muscle  derives  its  nerve  supply  from  the 
temporal  branch  of  the  temporo-facial  division  of  the  facial  nerve. 

The  apftiifiirnxin  extends  over  the  vertex  and  is  continuous  across  the  middle  line 
with  the  aponeurosis  of  the  opposite  side  ;  laterally  it  is  continued  over  the  temporal 
fascia  to  the  zygoma,  just  above  which  it  is  attached  to  that  fascia.  Connected 
with  the  lateral  portion  of  the  aponeurosis  are  the  attolens  and  attrahens  aurem 
muscles.  It  is  intimately  connected  with  the  skin  through  the  attachment  of  the 
superficial  fascia,  and  but  loosely  connected  with  the  pericranium  bv  the  connective 
tissue  which  intervenes,  thus  accounting  for  the  movement  of  the  integument 
when  the  occipito-frontalis  muscle  is  in  action. 

ACTION. — Contraction  of  the  anterior  belly  of  the  muscle  elevates  the  eye- 


!>i'  SURGICAL   A^^'m.MY. 

Imnv  and  produces  wrinkling  of  the  forehead  ;  if  contraction  be  continued,  it  draws 
the  scalp  forward,  and  pulls  up  the  skin  of  the  nose,  to  the  extent  even  of  moving 
the  naso-lahial  folds  ;  contraction  of  the  occipital  belly  draws  the  scalp  backward  ; 
and  alternate  contraction  of  the  two  bellies  niove<  the  scalp  backward  and  forward. 

DISSECTION. — Divide  the  aponeurosis  in  the  median  line,  and  make  another 
incision  at  its  junction  with  the  frontalis  muscle.  Reflect  the  aponeurosis  outward 
and  backward,  and  the  frontalis  muscle  downward. 

Areolar  tissue  layer. — The  mobility  of  the  scalp  depends  entirely  upon  the 
laxity  of  the  subjacent  areolar  tissue  layer:  it  is  this  layer  which  permits  ex- 
tensive Haps  of  the  scalp  to  be  torn  loose.  When  the  hairs  become  caught  in 
moving  machinery  the  entire  scalp  may  be  torn  off,  laying  this  tissue  bare. 
It  was  due  to  the  laxity  of  this  layer  that  the  American  Indian,  with  no  knowl- 
edge of  anatomy  or  surgery,  was  able  to  peel  off  the  scalp  with  so  much  ease. 
Exposure  of  the  skull  in  a  postmortem  examination  is  effected  by  peeling  off  the 
seal])  along  this  layer  of  tissue,  and  it  is  remarkable  with  what  ease  the  skull  can 
thus  be  exposed.  To  further  illustrate  the  laxity  of  this  tissue,  it  will  suffice  to 
relate  a  case  mentioned  by  the  late  I).  Hayes  Agnew  :  A  midwife  attending  a 
woman  in  child-birth  incised  the  child's  scalp,  thinking  it  the  protruding  bag  of 
waters.  Labor  pains  came  on,  and  the  head  protruded  through  the  scalp  wound 
with  the  entire  vault  of  the  skull  laid  bare. 

Tumors. — By  careful  examination  tumors  situated  above  the  occipito-frontalis 
aponeurosis  or  in  it  will  be  seen  to  be  freely  movable.  All  immovable  growths  of 
the  scalp  should  be  most  carefully  examined  before  extirpation,  for  they  are 
probably  beneath  the  aponeurosis  ;  a  tumor  originating  within  the  cranium  may 
force  its  way  outward  and  form  a  prominence  on  the  scalp. 

Wounds  involving  only  the  skin  and  superficial  fascia  of  the  scalp,  when  the 
occipito-frontalis  muscle  or  its  aponeurosis  has  not  been  divided,  do  not  gape, 
because  of  the  close  adherence  of  the  skin  to  the  superficial  fascia  and  of  the 
superficial  fascia  to  the  aponeurosis.  The  areolar  tissue  layer  permits  of  wide 
separation  of  the  edges  of  a  wound  which  divides  the  occipito-frontalis  aponeu- 
rosis. Antero-posterior  wounds  which  involve  the  aponeurosis  gape  but  little, 
while  the  edges  of  transverse  wounds  are  widely  separated  by  the  contraction  of 
the  occipito-frontalis  muscle.  The  great  vascularity  of  the  scalp  lessens  the  likeli- 
hood of  sloughing  and  gangrene.  A  large  flap  of  the  scalp  attached  by  but  a 
small  pedicle  is  much  less  likely  to  perish  than  a  flap  of  skin  torn  from  another 
part  of  the  body,  as  the  vessels  of  the  scalp  run  immediately  beneath  the  skin 
and  are  included  in  the  flap.  In  phlegmonous  erysipelas  and  in  deep  inflam- 
mation of  the  scalp  the  areolar  tissue  layer  becomes  infiltrated  with  pus  and  conse- 
quently sloughs.  As  the  vessels  are  superficial  to  this  layer  the  skin  does  not 


M  '.  I LP.  1 8  1 

necrose,  ulcerate,  and  allow  pointing,  and  for  this  reason  it  is  important  to  incise 
early. 

The  pericranium  (external  periosteum)  is  but  loosely  attached  to  the  bone, 
except  at  the  sutures,  where  the  union  is  firm.  In  lacerated  wounds  of  the  seal]) 
the  pericranium  is  frequently  stripped  from  the  skull  to  the  extent  of  exposing 
large  areas  of  bone.  The  pericranium  differs  in  its  functions  from  the  periosteum 
covering  other  bones  in  that,  if  the  periosteum  be  removed  to  any  extent  from 
another  hone,  the  part  of  the  bone  from  which  it  is  removed  will  most  probably 
necrose,  while  the  pericranium  may  be  stripped  from  a  considerable  part  of  the 
vault  of  the  cranium  without  necrosis  following.  This  is  due  to  the1  fact  that  the 
bones  of  the  skull  receive  their  blood  supply  chiefly  from  the  vessels  of  the  exter- 
nal (endosteal)  layer  of  the  dura  mater,  while  the  other  bones  are  nourished  to  a 
great  extent  through  their  pcriosteal  covering.  The  pericranium  at  the  sutures 
becomes  continuous  with  the  external  layer  of  the  dura  mater,  constituting  the 
so-called  intersutural  membrane.  It  is  also  continuous  with  the  dura  at  the  for- 
amina;  hence  it  is  that  inflammation  of  the  pericranium  may  extend  by  continuity 
and  involve  the  dura  mater,  producing  pachymeningitis. 

Collections  of  blood  or  pus  in  the  scalp  may  he  situated  superficial  to  the 
occipito-frontalis  aponeurosis,  between  the  aponeurosia  and  the  pericranium  or 
beneath  the  pericranium.  A  collection  superficial  to  the  aponeurosis  is  of  but 
little  moment,  since  the  density  of  the  superficial  fascia  causes  it  to  be  circum- 
scribed. Collections  in  the  areolar  tissue  layer,  between  the  aponeurosis  and  the 
pericranium,  are  limited  only  by  the  attachments  of  the  occipito-frontalis  muscle 
and  its  aponeurosis;  thus  they  may  undermine  the  entire  scalp  and  prove  serious 
if  not  evacuated  early.  Collections  beneath  the  pericranium  are  limited  to  a 
single  bone,  on  account  of  the  sutural  attachments  of  the  membrane.  Collections 
in  the  areolar  tissue  layer  call  for  drainage,  and  should  they  be  slow  in  healing, 
the  scalp  must  be  firmly  bandaged  in  order  to  arrest  the  movements  of  the  occipito- 
frontalis  muscle.  Hematomata  in  the  areolar  tissue  layer  are  uncommon,  except 
as  a  result  of  fissured  fracture  of  the  skull  with  rupture  of  one  of  the  branches  of 
the  middle  meningeal  artery,  or  of  the  superior  longitudinal  or  lateral  sinus,  as 
the  areolar  tissue  between  the  aponeurosis  and  the  pericranium  contains  but  very 
few  vessels.  Collections  of  blood  beneath  the  pericranium,  generally  termed 
cephalhematomata,  must  be  limited  to  one  bone,  since  the  membrane  dips  into 
the  sutures  and  becomes  continuous  with  the  dura  mater ;  they  are  usually 
congenital  and  due  to  pressure  upon  the  head  at  birth. 

In  septic  inflammation  of  the  scalp  infection  may  reach  the  superior 
longitudinal  sinus  through  the  parietal  emissary  vein  and  the  lateral  sinus 
through  the  occipital  and  posterior  auricular  veins  and  their  communications  with 
31 


482  SURGICAL   AXATO.MY. 

the  mastoid  vein  which  empties  into  the  lateral  sinus.  Through  the  anastomo-t •- 
between  the  diploic  veins  and  the  veins  of  the  pericranium  septic  material  in  the 
scalp  may  ivaeh  thr  sinus  ahe  parvie  and  the  cavernous  sinus  through  the  fronto- 
sphenoid  diploic  vein,  the  superior  petrosal  sinus  through  the  anterior  temporal 
diploic  vein,  and  the  lateral  sinus  through  the  posterior  temporal  and  occipital 
diploic  veins.  In  erysipelas,  abscess,  and  other  infectious  inflammations  of  the 
scalp  germs  may  enter  the  sinuses  through  these  various  routes  and  cause  throm- 
bosis, embolism,  and  pyemia. 

Temporal  fascia. — The  temporal  fascia  is  a  white,  shining  membrane,  which 
is  stronger  than  the  occipito-frontalis  aponeurosis  in  this  location,  and  which  gives 
attachment  by  its  under  surface  to  the  superficial  fibers  of  the  temporal  muscle. 
Above,  it  is  attached  to  the  entire  extent  of  the  temporal  ridge  as  a  single  layer; 
while  below,  it  divides  into  two  layers,  the  outer  of  which  is  attached  to  the 
external  and  the  inner  to  the  internal  border  of  the  upper  margin  of  the  zygo- 
matic  arch  and  zygomatic  process  of  the  malar  bone.  Between  these  two  layers 
are  seen  a  small  <]uantity  of  fat,  the  orbital  branch  of  the  middle  temporal  artery, 
and  the  temporal  branch  of  the  temporo-malar  or  orbital  branch  of  the  superior 
maxillary  nerve.  In  relation  with  its  outer  surface  is  the  extension  of  the  occipito- 
frontalis  aponeurosis,  the  orbicularis  palpebrarnm,  the  attolens  and  attrahens 
aurem  muscles,  the  temporal  vessels,  the  auriculo-temporal  nerve,  and  the  temporal 
branches  of  the  orbital  and  facial  nerves.  Immediately  above  the  zygoma  it  is 
pierced  by  the  middle  temporal  artery,  a  branch  of  the  temporal. 

Density  of  the  temporal  fascia. — Owing  to  the  density  of  this  fascia  abscesses 
beneath  it  very  rarely  point  upon  the  surface,  the  pus  passing  in  the  direction  of  least 
resistance — namely,  through  the  pterygo-maxillary  region  into  the  mouth  or  neck. 
Its  unyielding  nature  is  well  illustrated  by  a  ease  recorded  by  Denonvilliers :  "A 
woman  who  had  fallen  in  the  street  was  admitted  to  the  hospital  with  a  deep 
wound  in  the  temporal  region  ;  a  piece  of  bone  several  lines  in  length  was  found 
loose  at  the  bottom  of  the  wound  and  was  removed.  After  its  removal  the  finger 
could  be  passed  through  an  opening  with  an  unyielding  border,  and  came  in 
contact  with  some  soft  substance  beyond.  The  case  was  considered  one  of  com- 
pound fracture  of  the  squamous  portion  of  the  temporal  bone,  with  separation 
of  a  fragment  and  exposure  of  the  brain.  .A  bystander,  however,  noticed  that  the 
bone  removed  was  dry  and  white.  A  more  thorough  examination  of  the  wound 
revealed  the  fact  that  the  skull  was  uninjured,  that  the  supposed  hole  in  the  skull 
was  merely  a  laceration  of  the  temporal  fascia,  that  the  soft  matter  beyond  was 
muscle  and  not  brain,  and  that  the  fragment  removed  was  simply  a  piece  of  bone, 
which,  lying  on  the  ground,  had  been  driven  into  the  soft  parts  when  the  woman 
fell "  (Troves). 


PLATE  CXXVII. 


Supraorbital  a 
Supraorbital  n. 
Frontal  a. 


Infraorbital  br.of  facial  n. 
Temporal  br.  of  orbital  n. 
Malar  br.of  facial  n. 

Temporal  br.of  facial  n. 

Temporal  fascia 


Infratrochlear 

n. 

Nasa 

n 

I 

Auriculo-temporal  n. 
Middle  temporal  a. 
Anterior  auricular  a. 


w 


XSuperficial  temporal  v. 
^Superficial  temporal  a. 
^Facial  n. 

-Posterior  auricular  a. 
Internal  maxillary  a. 
Buccal  br.of  facial. n. 

Inframaxillary  br.of  facial  n. 


Mental  n          Mental  a. 


Labial  br\ 


Facial  v. 

Facial  a. 
Infraorbital  n. 
'Palpebral  br. 
Infraorbital  a. 
Nasal  br. 


'Supramaxillary  br.of  facial  n. 
Transverse  facial  a. 


TEMPORAL  FASCIA  AND  NERVES  OF  FACE. 
484 


PLATE  CXXVIII. 


Temporal  m. 


Superficial  temporal  a. 
Facial  n. 

Internal  maxillary  a. 

Temporo-maxillary  v. 

Masseter  m. 
Platysma  myoides  m. 


TEMPORAL  MUSCLE. 
485 


PLATE  GXXIX, 


INCISIONS  FOR  DISSECTION  AND  LINES  FOR  VESSELS  AND  NERVES. 

487 


FACE.  489 

DISSECTION. — The  temporal  fascia  should  now  be  detached  from  the  /ygomatic 
arch  and  reflected  upward,  wlien  the  greater  portion  of  the  temporal  muscle  and 
a  quantity  of  fat  overlying  the  muscle  above  the  zygoma  will  be  exposed.  The 
tendon  of  insertion  of  the  muscle  will  be  seen  in  dissecting  the  face. 

The  temporal  muscle,  broad,  flat,  and  triangular,  is  situated  on  the  side  of 
the  head,  and  occupies  the  temporal  fossa.  It  arises  from  the  under  surface  of  the 
temporal  fascia  and  from  the  whole  of  the  temporal  fossa,  whence  its  libers  descend 
and  converge  to  a  tendon  which  passes  under  the  zygornatic  arch  to  be  inserted 
into  the  apex,  the  inner  surface,  and  the  fore  part  of  the  coronoid  process  of  the 
lower  jaw  down  to  the  last  molar  tooth. 

BLOOD  SUPPLY. — From  the  middle  and  deep  temporal  arteries. 

NEK VK  SUTLY. — Derived  from  the  temporal  branches  of  the  inferior  ma.i-illary 
in  i'/ 1 . 

ACTION. — The  action  of  the  temporal  muscle  is  to  elevate  the  lower  jaw  ;  its 
posterior  fibers  also  assist  in  drawing  the  lower  jaw  backward  after  other  muscles 
have  carried  it  forward. 


FACE. 

DISSECTION. — The  dissection  of  the  face  should  follow  that  of  the  scalp. 
The  head  should  be  placed  in  the  same  position  as  for  the  dissection  of  the 
scalp,  but  slightly  lower,  and  turned  so  that  the  side  of  the  face  to  be  dissected 
is  upward.  The  cheeks  and  nostrils  should  be  distended  with  cotton  or  oakum 
and  the  lips  sewed  together.  The  muscles  and  vessels  should  be  dissected  on 
one  side  of  the  face  and  the  nerves  on  the  other.  The  incisions  are  made  as 
follows:  The  first  incision  is  made  from  the  nasal  eminence  along  the  median  line 
of  the  nose,  around  the  aperture  of  the  nostril,  along  the  median  line  of  the  upper 
lip,  around  the  mouth  along  the  line  where  the  skin  joins  the  mucous  membrane 
to  the  median  line  of  the  lower  lip,  and  thence  to  the  point  of  the  chin.  A  second 
incision  is  carried  along  the  lower  border  of  the  jaw  to  the  angle  of  the  jaw,  then 
upward  to  the  lobe  of  the  ear.  Reflect  the  skin  outward.  The  facial  muscles 
(muscles  of  expression)  are  inserted  partly  into  the  skin,  and  great  care  must  be 
taken  that  they  are  not  removed  with  the  skin. 

The  skin  of  the  face  is  remarkably  thin,  and  freely  supplied  with  vessels  and 
nerves.  On  account  of  the  free  blood  supply  it  is  a  common  site  of  nevi,  except 
over  the  chin,  where  it  is  peculiarly  dense  and  adherent  to  the  parts  beneath. 
The  skin  covering  the  eyelids  and  the  bridge  of  the  nose,  owing  to  the  presence 


4  !>0  SURGICAL    A  ^  ATOMY. 

of  a  layer  of  lax  cellular  tissue,  is  luoselv  aillicreiit  t<>  the  parts  beneath.  Over  the 
cartilages  of  the  nose  the  skin  is  so  intimately  adherent  to  the  tissues  beneath  that 
it  is  removed  with  difficulty.  It  is  very  freely  supplied  with  sebaceous  and  sudor- 
iferous glands,  and  hence  is  commonly  the  site  of  acne  and  eruptions  which 
especially  involve  the  seha-ceous  follicles;  it  is  also  the  site  of  sebaceous  tumors. 
Facial  abscesses  usually  point  quickly  and  seldom  attain  large  size. 

The  superficial  fascia — the  cellular  tissue  layer  of  the  face — contains  a  con- 
siderable amount  of  fat,  except  in  the  eyelids  and  over  the  bridge  of  the  nose.  The 
laxity  of  the  cellular  tissue  favors  the  spreading  of  infiltrations,  so  that  the  cheeks 
and  other  parts  of  the  face  may  become  greatly  swollen.  In  general  dropsy  the 
face  soon  becomes  puffy,  the  edema  first  appearing,  as  a  rule,  in  the  lax  areolar 
tissue  of  the  lower  eyelid.  The  soft  tissues  of  the  cheek  favor  the  spread  of 
destructive  processes.  In  cam-rum  oris — a  form  of  gangrene  of  the  mouth  attack- 
ing the  young — the  whole  cheek  may  be  lost  in  a  few  days.  (Ireat  contraction  is 
apt  to  follow  upon  loss  of  substance,  so  that  the  jaw  may  be  firmly  closed  in  some 
cases,  as  is  seen  a  ft  el' recovery  from  deep  ulceration  (Treves).  The  mobility  of  the 
tissues  of  the  face  renders  this  region  favorable  for  the  performance  of  plastic 
operations,  and  their  vascularity  insures  a  prompt  and  perfect  union.  Notwith- 
standing the  fact  that  there  is  a  large  quantity  of  fat  in  the  subcutaneous  tissue, 
fatty  tumors  are  rarely  seen  in  this  region.  The  thickness  of  the  tissues  of  the 
cheeks  and  lips  favors  the  embedding  of  foreign  substances  in  these  parts.  Thus, 
a  tooth  which  has  been  knocked  out  has  remained  embedded  in  the  lip.  Henry 
Smith  reported  a  remarkable  cast'  in  which  he  removed  a  piece  of  tobacco-pipe 
three  inches  long  from  the  cheek,  where  it  had  remained  for  several  years. 

DISSECTION. — The  superficial  fascia — underlying  which  are  the  muscles, 
vessels,  and  nerves — should  be  removed  in  the  same  manner  as  the  skin,  taking- 
care  not  to  disturb  the  muscles.  As  the  superficial  fascia  is  not  easily  removed 
in  a  continuous  layer,  it  may  be  taken  away  in  sections,  the  dissection  being  made 
in  the  line  of  the  muscular  fibers ;  this  is  necessary,  too,  in  order  to  avoid  dividing 
the  blood-vessels  and  nerves  of  the  face.  The  removal  of  the  fascia  in  this  manner 
exposes  the  muscles,  the  vessels,  and  the  nerves. 

The  Muscles  of  the  Face  (muscles  of  expression)  are  divided  into  three 
groups :  those  of  the  nose,  those  of  the  eyebrows  and  eyelids,  and  those  of  the 
mouth — i.  p.,  nasal,  palpebral,  and  oral. 

The  Muscles  of  the  Nose  are  the  pyramidalis  nasi,  the  compressor  nasi,  the 
levator  labii  superioris  alseque  nasi,  the  dilator  naris,  and  the  depressor  a  la.-  nasi. 

The  pyramidalis  nasi  muscle  covers  the  nasal  bone,  and  is  continuous  above 
with  the  frontalis  muscle,  where  it  is  attached  to  the  deep  surface  of  the  inter- 
superciliary  integument.  It  arises  from  the  aponeurosis  over  the  cartilage  of 


PLATE  CXXX. 


Pjramidahs  nail  m. 

Orb.cularis  palpebrarum  m. 
Frontalis  m. 


-  apor.euros.s 
Attrahens  aurem  m. 

•ttollens  auiem  m. 

Retrahens  aurem  m. 


Occipitalis  m. 


Depressor  anguii  oris  m. 


MUSCLES  OF  FACE  AND  SCALP. 
491 


tysma  myoides  m. 


FACE.  la- 

the nose,  where  it  joins  the  lower  edge  of  the  nasal  bone  and  the  compressor 
nasi  muscle. 

NKKVK  STPPLY. — From  tlie  infra-orbital  branch  of  the  temporo-facial  division 
of  the  facial  nerve. 

ACTION. — It  renders  the  skin  over  the  cartilages  tense,  and  that  over  the  root 
of  the  nose  lax.  thus  forming  the  transverse  crease  at  the  root  of  the  nose. 

The  compressor  nasi  muscle  is  triangular  in  shape,  arises  by  its  apex  from 
the  canine  fossa  of  the  superior  maxillary  hone,  and  ends  in  the  aponeurosis 
covering  the  cartilaginous  part  of  the  nose,  blending  with  the  corresponding  muscle 
of  the  opposite  side.  The  origin  of  this  muscle  is  concealed  by  the  levator  labii 
superior!*  aheque  nasi  muscle. 

NF.KVE  STPPLY. — From  the  infra-orbital  branch  of  the  upper  division  of  the 
facial  nerve. 

ACTION. — It  throws  the  skin  at  the  side  of  the  nose  into  vertical  wrinkles,  aids 
in  the  elevation  of  the  upper  lip,  and  slightly  compresses  the  cartilaginous  ridge 
of  the  nose. 

When  the  compressor  nasi  muscle  is  reflected  from  the  median  line  outward, 
the  superficial  branch  (naso-lahial)  of  the  nasal  nerve,  which  becomes  subcutaneous 
between  the  nasal  bone  and  the  lateral  nasal  cartilage,  will  be  seen  running  down- 
ward to  the  tip  of  the  nose. 

The  levator  labii  superioris  alaeque  nasi  muscle,  placed  by  the  side  of  the 
nose  and  overlapping  the  origin  of  the  compressor  nasi  muscle,  arises  from  the  upper 
part  of  the  nasal  process  of  the  superior  maxilla.  It  descends,  and  divides  into  two 
portions :  the  inner  and  smaller  part  is  inserted  into  the  inner  side  of  the  ala  nasi, 
and  the  outer  into  the  upper  lip,  blending  with  the  orbicularis  oris  muscle.  It 
is  partially  overlapped  near  its  origin  by  the  orbicularis  palpebrarum  muscle. 

NERVE  SUPPLY. — From  the  infra-orbital  branch  of  the  facial  nerve. 

ACTION. — It  raises  the  inner  half  of  the  upper  lip,  and  draws  outward  the 
wing  of  the  nose,  thus  dilating  the  anterior  naris. 

The  dilator  naris  muscle  consists  of  two  portions — an  anterior  and  a  posterior. 
The  anterior  portion  is  a  thin  fasciculus  which  passes  from  the  lower  edge  of  the 
cartilage  of  the  wing  of  the  nose  to  the  integument  over  the  ala ;  the  posterior 
portion  arises  from  the  margin  of  the  nasal  notch  of  the  superior  maxilla  and 
from  the  outer  surface  of  the  sesamoid  cartilages  of  the  nose,  and  is  inserted  into 
the  skin  over  the  back  and  lower  margin  of  the  ala  of  the  nose. 

NERVE  SUPPLY. — From  the  infra-orbital  branch  of  the  facial  nerve. 

ACTION. — It  enlarges  the  anterior  naris  by  raising  and  everting  its  outer  edge, 
thus  counteracting  its  tendency  to  be  closed  by  atmospheric  pressure.  In  condi- 
tions occasioning  dyspnea — e.  g.,  laryngeal  or  tracheal  obstruction — the  action  of 


!'.U  SURGICAL    A  \ATOMY. 

these  muscles  can  plainly  he  seen,  and  constitutes  one  ol'  the  signs  which  indicate 
tracheotomy  or  intubation. 

The  depressor  alae  nasi  is  a  short.  Hat  muscle  which  may  lie  exposed  when  the 
upper  lip  is  everted  and  its  mucous  membrane  removed  from  the  side  of  the  labial 
frenum.  It  arises  from  the  incisive  fossa  of  the  superior  maxilla,  whence  its  fibers 
ascend  to  be  inserted  into  the  septum  nasi  and  the  posterior  lower  part  of  the  wing 
of  the  no 

NICRVK  SUPPLY. — From  the  buccal  branch  of  the  cervico-facial  division  of  the 
facial  nerve. 

ACTION. — It  draws  downward  and  inverts  the  edge  of  the  nasal  cartilam •.-. 

The  Muscles  of  the  Eyelids  and  Eyebrows  are  the  orbicularis  palpebrarum, 
the  corrugator  supercilii,  the  levator  palpebrse  superioris,  and  the  tensor  tarsi. 

Tendo  oculi  (tendo  palpebrarum). — Before  examining  the  orbicularis  palpe- 
brarum the  tendo  oculi  (internal  tarsal  ligament)  is  to  be  noted.  It  is  a  short 
tendon,  about  one-sixth  of  an  inch  in  length  by  one-twelfth  of  an  inch  in  breadth, 
and  can  readily  be  felt  at  the  inner  angle  of  the  eye  after  drawing  the  eyelids 
outward.  It  is  attached  to  the  nasal  process  of  the  superior  maxilla  in  front  of 
the  lacrymal  groove,  passes  transversely  outward  in  front  of  the  lacrymal  sac,  and 
divides  into  two  portions,  separated  by  the  caruneula  lachrymalis  ;  the  upper  portion 
is  attached  to  the  inner  extremity  of  the  upper,  and  the  lower  to  the  inner  extrem- 
ity of  the  lower,  tarsal  cartilage.  As  the  tendon  crosses  the  lacrymal  sac  it  gives 
off  a  strong  aponeurotic  lamina,  which  covers  the  sac  and  is  attached  to  the  margin 
of  the  lacrymal  groove.  This  expansion  will  be  seen  on  reflecting  that  portion  of 
the  orbicularis  palpebrarum  muscle  which  covers  the  lacrymal  sac.  To  puncture 
the  lacrymal  sac  a  knife  is  inserted  below  the  tendo  oculi  in  a  direction  downward 
and  a  little  backward,  dividing  the  skin,  the  orbicularis  palpebrarum  muscle, 
and  the  fibrous  expansion  derived  from  the  tendo  oculi.  The  angular  artery  and 
vein  are  situated  on  the  inner  side  of  the  incision. 

The  external  tarsal  ligament  extends,  undivided,  transversely  inward  from 
the  edge  of  the  frontal  process  of  the  malar  bone  to  the  adjacent  outer  extremities 
of  the  two  tarsal  cartilages. 

The  orbicularis  palpebrarum  (orbicularis  oculi,  sphincter  oculi)  is  a  thin. 
broad  muscle  which  surrounds  the  margin  of  the  orbit  and  the  eyelids,  forming  a 
sphincter  ;  it  is  continuous,  above,  with  the  fibers  of  the  frontalis  muscle.  It  arises 
from  the  internal  angular  process  of  the  frontal  bone,  the  nasal  process  of  the 
superior  maxilla,  the  tendo  oculi,  and  the  lower  margin  of  the  orbit.  From  this 
origin  the  fibers  are  directed  outward,  forming  a  series  of  oval  curves  which  cover 
the  eyelids,  surround  the  margin  of  the  orbit,  and  spread  over  the  forehead. 
temple,  and  cheek.  The  central  fibers,  occupying  the  eyelids  and  connected  inter- 


PLATE  CXXXI. 


Pulley 


Superior  rectus  m. 


Tendon  of  superior  oblique  m 


Orbital  fat 

Inferior  rectus  m 

Inferior  oblique  m 


Corrugator  Supercilii  m. 

Puncta  lachrymalia 
Meibomian  gland 


Conjunctiva 


Tensor  tarsi  m. 


TENSOR  TARSI  AND  CORRUCATOR  SUPERCILII  MUSCLES. 
496 


FA  el-:.  -Jit? 

nally  with  the  tendo  oeuli  and  externally  witli  the  external  tarsal  ligament  and 
the  malar  bone,  constitute  tln.Q  palpebral  portion  of  (lie  muscle.  The  libers  of  this 
portion,  which  are  in  immediate  relation  with  the  eyelashes,  have  been  docrilied 
as  the  i-Hliii-i/  muscle;  but  this,  however,  must  not  be  confounded  with  the  ciliary 
muscle  proper — the  muscle  of  visual  accommodation.  More  peripheral  fibers  con- 
stitute the  oi-tilfiil  /I'nii'iii  of  the  muscle.  The  latter  arise  from  the  internal  angular 
process  of  the  frontal  bone  and  from  the  nasal  process  of  the  superior  maxillary 
bone,  and  are  distributed  around  the  margin  of  the  orbit.  They  are  continuous 
above  with  the  frontalis  and  corrugator  supercilii  muscles,  and  extend  outward 
upon  the  cheek  to  mingle  with  the  elevators  of  the  upper  lip  and  nose  and  with 
the  zygomaticus  minor  muscle. 

NKKVE  STPPLY. — From  the  temporal  and  malar  branches  of  the  temporo-facial 
division  of  the  facial  nerve  ;  hence  in  paralysis  of  this  nerve  the  eyelids  on  the 
paralyzed  side  can  not  be  closed. 

ACTION". — The  orbicularis  palpebrarum  muscle  closes  the  eyelids  and  protects 
the  eye.  The  palpebral  portion  of  the  muscle  contracts  during  winking.  Con- 
traction of  the  orbital  portion  presses  the  eyeball  backward  into  the  orbit  and 
draws  the  soft  parts  covering  the  margin  of  the  orbit  around  the  eyeball,  thus 
protecting  it  from  injury.  While  this  cushion  of  tissue  may  be  severely  bruised, 
as  is  seen  in  a  "black"  eye,  the  eyeball  itself  is  rarely  injured.  As  the  outer 
portion  of  the  orbicularis  is  mingled  with  the  fibers  of  the  frontalis  muscle 
and  the  elevators  of  the  upper  lip  and  nose,  slight  depression  of  the  eyebrow 
and  elevation  of  the  upper  lip  and  of  the  wing  of  the  nose  follow  contraction 
of  this  portion.  Strong  contraction  of  the  entire  muscle  holds  the  eye  firmly  in 
the  orbit,  thus  protecting  it  against  the  severe  strain  in  violent  coughing,  sneezing, 
and  vomiting,  during  which  acts  the  muscle  usually  contracts  spasmodically. 
Contraction  of  the  palpebral  portion  of  the  muscle  following  that  of  the  orbicular 
portion  tends  to  draw  the  lids  slightly  inward,  thus  directing  the  tears  to  the  inner 
angle  of  the  fissure  between  the  eyelids,  near  which  are  situated  the  puncta  lachry- 
malia. 

The  tensor  tarsi  (Homer's  muscle)  is  a  small  muscle,  really  a  deep  portion  of 
the  orbicularis  palpebrarum,  situated  at  the  inner  angle  of  the  orbit  behind  the 
tendo  oculi.  To  expose  it  it  is  necessary  to  cut  perpendicularly  through  the  middle 
of  the  upper  and  lower  eyelids,  when  the  nasal  half  of  each  lid  should  be  reflected 
inward  and  the  mucous  membrane  removed.  The  muscle  will  be  seen  to  arise  from 
the  ridge  on  the  lacrymal  bone.  It  passes  outward  behind  the  lacrymal  sac  and 
divides  into  two  portions  which  cover  the  posterior  aspect  of  the  canaliculi.  The 
two  portions  terminate  in  the  inner  ends  of  the  upper  and  lower  tarsal  cartilages 
near  the  puncta  lachrymalia. 

32 


SURGICAL    A\  ATOMY. 

NHIVK  SrrpLY. — From  tin-  infra-orbital  branch  of  the  temporo-facial  division 
of  the  facial  nerve. 

ACTION. — It  compresses  the  lacrymal  sac. 

The  corrugator  supercilii  muscle  arises  from  the  inner  end  of  the  superciliary 
ridge  of  the  frontal  hone.  Its  lihers  are  directed  outward  and  a  little  upward  to 
the  under  surface  of  the  orhicularis  palpebrarum  and  frontalis  muscles,  to  he 
inserted  into  the  former  over  the  middle  of  the  supra-orbital  arch. 

XKRVE  SUPPLY. — From  the  temporal  hranch  of  the  temporo-facial  division  of 
the  facial  nerve. 

ACTION. — It  draws  the  eyebrow  downward  and  inward,  thus  making  the 
vertical  wrinkle  of  the  forehead  at  the  inner  extremity  of  the  eyebrow. 

DISSECTION. — The  nasal  half  of  the  orhicularis  palpebrarum  and  a  small  part 
of  the  frontalis  muscle  having  been  reflected  inward,  the  corrugator  supercilii  is 
exposed. 

The  levator  palpebrae  superioris  muscle. — By  reflecting  the  outer  as  well 
as  the  nasal  half  of  the  orhicularis  palpebrarum  muscle,  and  detaching  the  orbit  o- 
tarsal  ligament  from  the  superior  orbital  margin  and  reflecting  the  ligament 
downward,  the  insertion  of  the  levator  palpebraj  superioris  muscle  by  a  broad 
aponeurosis  into  the  upper  border  of  the  tarsal  cartilage  of  the  upper  eyelid 
can  be  seen. 

The  Muscles  of  the  Mouth  are  the  orhicularis  oris,  the  levator  labii  supe- 
rioris, the  levator  anguli  oris,  the  zygomaticus  major,  the  zygomaticus  minor,  the 
buccinator,  the  risorius,  the  depressor  labii  inferioris,  the  depressor  anguli  oris,  and 
the  levator  labii  inferioris. 

The  risorius  muscle  (Santorini's  muscle),  a  part  of  the  platysma  myoides, 
consists  of  a  thin  bundle  of  fibers  which  arises  from  the  fascia  covering  the 
masseter  muscle  and  parotid  gland,  and  passes  horizontally  forward  to  the  angle 
of  the  mouth,  where  it  joins  the  fibers  of  the  orbicularis  oris  and  depressor  anguli 
oris  muscles ;  some  of  its  fibers  pass  to  the  skin  at  the  angle  of  the  mouth. 

NERVE  SUPPLY. — From  the  buccal  branch  of  the  lower  division  of  the  facial 
nerve,  which  enters  it  from  beneath. 

ACTION. — It  retracts  the  corner  of  the  mouth.  Its  contraction  during  certain 
conditions,  as  in  tetanus,  causes  the  "  risus  sardonicus"  of  the  old  authors. 

The  orbicularis  oris  muscle  (sphincter  oris),  nearly  an  inch  in  breadth,  sur- 
rounds the  mouth,  forming  a  sphincter ;  at  its  periphery  it  unites  with  several 
muscles  which  act  upon  that  aperture.  It  consists  of  two  parts — an  inner,  central, 
or  labial  part,  and  an  outer,  peripheral,  or  facial  part ;  the  two  differing  in  appear- 
ance and  in  the  arrangement  of  fibers,  like  the  orbicularis  palpebrarum  muscle. 
The  inner,  central,  or  labial  portion  consists  of  pale,  thin  fibers,  fine  in  texture, 


FA  <•!•:.  199 

corn 'S]  Kim  Is  in  position  with  the  red  margin  <>f  the  lips,  and  has  no  bony  attach- 
ment, hut  is  continuous  around  tlic  angles  of  llie  mouth  from  one  lip  to  the  other. 
The  outer,  peripheral,  or  faeial  part  is  thinner  and  wider  than  the  lahial,  and  has  a 
bony  attachment  as  well  as  eonnection  with  the  adjacent  muscles.  In  the  upper  lip 
the  orhicnlaris  oris  mnscle  is  attached  at  each  side  of  the  middle  line  to  the  lower 
part  of  the  septum  nasi  by  naso-labial  slips,  and  to  the  alveolar  border  of  the 
upper  jaw  opposite  the  incisor  teeth  ;  in  llie  lower  lip  it  is  attached  to  the  alveolar 
border  of  the  lower  jaw  opposite  the  canine  teeth  by  a  single  fasciculus  (nmscnli 
iucisivi).  The  cutaneous  surface  of  the  muscle  is  intimately  connected  with  the 
skin  of  the  lips  and  surrounding  parts.  The  intimacy  of  this  union  is  so  great  in 
some  instances  that  the  mouth  is  surrounded  by  radiating  wrinkles,  especially 
marked  in  the  upper  lips  of  women.  The  labial  integument  of  the  male  probably 
contains  fewer  wrinkles  on  account  of  the  presence  of  large  hair-bulbs.  The  deep 
surface  of  the  orbicularis  oris  is  covered  by  mucous  membrane,  between  which  and 
the  muscle,  in  the  submucous  tissue,  are  the  coronary  arteries  and  the  labial  glands. 

NKKVI:  STPPLY. — From  the  buceal  and  supra-maxillary  branches  of  the 
cervico-facial  division  of  the  facial  nerve. 

ACTION. — \Vhen  the  facial  and  labial  portions  act  conjointly,  they  press 
together  and  project  the  lips.  The  labial  fibers  acting  alone  bring  the  lips  and 
the  angles  of  the  mouth  together  and  invert  the  lips.  The  facial  fibers  acting 
alone  press  the  lips  against  the  alveolar  borders  of  the  jaws,  and,  at  the  same  time, 
evert  the  lips.  The  orbicularis  oris  is  the  antagonist  of  all  those  muscles  which 
converge  to  the  lips  from  the  various  parts  of  the  face.  Hypertrophy  of  the 
orbicularis  oris  or,  rather,  an  increase  of  the  connective  tissue,  particularly  of  tin- 
portion  in  the  upper  lip,  to  the  extent  of  producing  a  considerable  deformity,  is 
sometimes  seen,  and  indicates  a  plastic  operation  involving  the  removal  of  a  trans- 
verse, wedge-shaped  section  from  the  lip. 

The  levator  labii  superioris  muscle  (levator  labii  proprius)  arises  from  the 
superior  maxilla  above  the  infra-orbital  foramen,  and  is  inserted  into  the  upper 
lip,  its  fibers  blending  with  the  orbicularis  oris  muscle.  At  its  origin  it  is  over- 
lapped by  the  orbicularis  palpebrarum,  and  covers  the  infra-orbital  vessels  and 
nerves.  It  is  a  landmark  in  exposing  the  infra-orbital  nerve. 

NERVE  SUPPLY. — From  the  infra-orbital  branch  of  the  upper  division  of  the 
facial  nerve. 

ACTION. — It  raises  the  upper  lip,  at  the  same  time  making  prominent  the  skin 
below  the  eye. 

DISSECTION. — The  levator  labii  superioris  muscle  is  to  be  reflected  downward 
from  its  origin,  when  will  be  exposed  the  levator  anguli  oris,  the  infra-orbital 
plexus  of  nerves,  and  the  infra-orbital  vessels. 


.-><><>  SURGICAL    .\\ATOMY. 

The  levator  anguli  oris  muscle  (nmsculus  caninus)  arises  from  tin-  canine 
I'M-- ii  of  the  superior  maxilla  below  the  infra-orbital  foramen,  and  is  inserted  into 
the  angle  of  the  mouth,  supcrlirial  to  the  hueeinator  muscle,  its  (ihers  Mending 
with  the  urhieularis  oris,  the  y.ygomatici,  and  the  dejiressor  anguli  oris  muscle. 

NKIJVK  SUPPLY. — From  the  infra-orhital  branch  of  the  upper  division  of  the 
faeial  nerve. 

ACTION*. — It  raises  and  draws  inward  the  angle  of  the  mouth. 

The  depressor  labii  inferioris  muscle  (quadratus  menti)  arises  from  the 
oblique  line  of  the  lower  jaw  by  a  wide  origin,  extending  from  a  point  below 
the  foramen  mentale  nearly  to  the  symphysis.  Its  fibers  are  assoeiated  with 
those  of  the  muscle  of  the  opposite  side,  ascend,  and  are  inserted  into  the  integu- 
ment of  the  lower  lip,  blending  with  the  orbicularis  oris.  Its  outer  border  is 
overlapped  by  the  depressor  anguli  oris  muscle. 

NI:I;\  i:  SUPPLY. — From  the  supra-maxillary  branch  of  the  cervico-facial  divi- 
sion of  the  facial  nerve. 

ACTION. — It  depresses  and  everts  the  lip. 

The  depressor  anguli  oris  muscle,  triangular  in  shape,  hence  also  called 
triangularis  oris,  arises  from  the  oblique  line  of  the  lower  jaw  external  to 
the  depressor  labii  inferioris  muscles.  Its  fibers  ascend,  to  be  inserted  into  the 
angle  of  the  month,  intermingling  with  the  zygomatici,  the  levator  anguli  oris, 
the  risorius,  and  the  orbicularis  oris  muscle.  Its  outer  border  overlaps  the 
anterior  part  of  the  buccinator  muscle. 

NERVE  SUPPLY. — From  the  supra-maxillary  branch  of  the  cervico-facial  divi- 
sion of  the  facial  nerve. 

ACTION. — It  draws  the  angle  of  the  mouth  downward  and  outward,  producing 
an  expression  of  sorrow. 

The  levator  labii  inferioris,  or  levator  menti,  is  a  small  muscle  seen  by 
everting  the  lip  and  dissecting  off  the  mucous  membrane  on  each  side  of  the 
labial  frenum.  It  arises  from  the  fossa  below  the  incisor  teeth,  near  the  symphysis. 
Its  fibers  descend,  and  are  inserted  into  the  integument  of  the  chin. 

NERVE  SUPPLY. — From  the  supra-maxillary  branch  of  the  cervico-facial  divi- 
sion of  the  facial  nerve. 

ACTION.- — It  assists  in  raising  the  lower  lip,  at  the  same  time  wrinkling  the 
integument  of  the  chin  over  the  point  of  its  insertion. 

The  zygomatic  muscles  pass  obliquely  from  the  /ygomatic  arch  to  the  upper 
lip  and  angle  of  the  mouth.  The  zygomaticus  major  arises  from  the  outer  part 
of  the  malar  bone  in  front  of  the  suture,  between  it  and  the  zygoma  ;  its  fibers  pass 
obliquely  downward  and  inward,  to  be  inserted  into  the  angle  of  the  mouth, 
blending  with  the  fibers  of  the  orbicularis  and  depressor  anguli  oris  muscles. 


/•'.I  <'H.  r.Ol 

The  zygomaticus  minor  ari-es  from  tin-  outer  ]>;irt  of  tlic  malar  bone,  anterior  to 
the  zygomaticus  major,  and  behind  the  suture  between  the  malar  bone  and  tbe 
superior  maxilla  ;  its  fibers  pass  downward  and  inward,  to  be  inserted  into  the 
lower  border  of  the  levator  labii  superioris  muscle.  It  is  often  absent. 

NI:I:VK  Sri'pLY. — From  the  infra-orbital  branch  of  the  temporo-facial  divi- 
sion of  the  facial  nerve. 

ACTION. — Tbe  xygomaticus  major  draws  the  corner  of  the  mouth  upward  and 
backward  ;  the  /ygomatieus  minor  assists  the  levator  labii  superioris  muscle  in 
raising  the  upper  lip. 

Bucco-pharyngeal  fascia. — Before  making  a  dissection  of  the  buccinator 
muscle,  the  thin  layer  of  fascia  which  covers  and  adheres  closely  to  its  surface 
should  be  studied  ;  it  is  attached  to  the  alveolar  borders  of  the  superior  and  infe- 
rior maxillary  bones,  and  posteriorly,  where  it  is  thickest,  is  continuous  with  the 
fascia  over  the  constrictors  of  the  pharynx.  It  is  called  by  Holden  the  "  bucco- 
pharyngeal  fascia,"  since  it  supports  and  strengthens  the  walls  of  the  pharynx  and 
mouth.  The  density  of  the  buccal  fascia  offers  a  barrier  to  the  escape  of  pus  into 
the  mouth  or  pharynx  from  an  abscess  in  the  cheek. 

The  buccinator,  quadrangular  in  form,  is  a  thin,  flat  muscle  which  occupies 
the  interval  between  the  jaws  at  the  side  of  the  face.  It  arises  from  the  outer 
surface  of  the  alveolar  borders  opposite  the  middle  and  posterior  molar  teeth  of  the 
superior  and  inferior  maxilla?,  and  behind  from  the  pterygo-maxillary  ligament. 
The  pterygo-mn.i •illnr;/  lii/nnK'nt  is  a  fibrous  band  extending  from  the  apex  (hamular 
process)  of  the  internal  pterygoid  plate  of  the  pterygoid  process  to  the  posterior 
extremity  of  the  internal  oblique  line  (mylo-hyoid  ridge)  of  the  lower  jaw  ;  it 
separates  the  buccinator  muscle  from  the  superior  constrictor  of  the  pharynx. 
The  fibers  of  the  buccinator  pass  forward,  to  be  inserted  into  the  orbicularis  oris 
muscle  at  the  angle  of  the  mouth.  The  central  fibers  intersect  one  another,  while 
the  upper  fibers  pass  to  the  upper  lip  and  the  lower  fibers  to  the  lower  lip.  In 
relation  with  the  superficial  surface  of  the  buccinator  muscle  is  a  large  mass  of  fat 
(buccal  pad),  which  separates  it  from  the  ramus  of  the  lower  jaw,  the  masseter 
muscle,  a  small  portion  of  the  temporal  muscle,  and  the  muscles  converging  to  the 
angle  of  the  mouth.  Absorption  of  the  fat  overlying  the  muscle  is  followed  by 
sinking  of  the  cheek,  as  seen  in  persons  who  are  emaciated.  In  compression  of  the 
brain  the  flapping  of  the  cheeks  in  breathing  is  the  result  of  paralysis  of  the  nerve 
supplying  the  buccinator,  while  the  stertorous  breathing  (snoring)  is  the  result  of 
paralysis  of  the  nerves  of  the  soft  palate.  The  duct  of  the  parotid  gland  (Stenson's 
duct),  which  pierces  the  buccinator  muscle  opposite  the  second  molar  tooth  of  the 
superior  maxilla,  crosses  the  upper  part  of  the  muscle  obliquely,  at  about  a  finger's 
breadth  below  the  zygoma.  It  is  also  crossed  by  the  facial  artery  and  vein  and 


502  SURGICAL   ANATOMY. 

by  branches  of  the   facial    nerve.      Internally  il  is  lined   l>y  the  mucous  membrane 

n!'   the   month;   between    this   and    the   muscle    lie  a    number   of    racemo.~. 

Called  the  btlccal   glands.       A    few  of   these  glands  are   tonild  on  llie  oilier  surface  of 

the  muscle  and  are  called  molar  glands. 

NEJIVK  Sri'iM.v. —  I'Yom  the  facial  nerve.  The  long  luiccal  nerve,  a  hraneli  of 
the  inferior  maxillary,  pierces  the  buccinator  muscle  on  its  way  to  supply  the 
mucous  niemhrane  of  the  month. 

ACTION. — The  two  huccinator  muscles  widen  the  aperture  of  the  mouth 
transversely  and  contract  and  compress  the  cheeks  so  that  during  mastication  the 
food  will  not  remain  hetwcen  the  cheeks  and  the  teeth.  When  but  one  muscle 
acts,  the  angle  of  the  mouth  is  drawn  to  that  side,  and  the  cheek  is  wrinkled  ; 
when  whistling,  the  muscle  contracts  and  prevents  bulging  of  the  cheeks. 

It  is  hardly  fair  to  the  earnest  dissector  to  leave  this  subject  without  the 
consoling  reminder  that  the  most  expert  dissectors  can  not  bring  out  these  muscle.- 
in  the  cadaver  as  they  are  shown  in  the  anatomic  plates.  It  must  be  remembered 
that  some  of  the  facial  muscles  belong  to  the  panniculus  carnosus  group,  so  exten- 
sive in  animals  but  so  limited  in  man.  In  some  faces  the  musculature  is  a  com- 
plex network  of  subcutaneous  fibers  running  in  all  directions.  In  a  muscular 
subject  a  large  number  of  distinct  fasciculi  are  seen  crossing  one  another,  and  more 
or  less  merged  with  the  constant  muscles  of  the  face.  This  difference  in  the 
amount  of  facial  musculature  undoubtedly  accounts  for  much  of  the  variation  in 
the  amount  of  facial  wrinkling  observed  in  different  persons.  It  is  safe  to  say  that 
a  dissection  of  the  muscles  of  the  face  with  their  boundaries  as  well  defined  as 
shown  in  pictures  does  more  credit  to  the  dissector's  skill  in  imitating  a  diagram 
than  to  any  painstaking  effort  to  exhibit  the  natural  state  of  the  parts. 

The  Facial  Artery,  a  branch  of  the  external  carotid,  enters  the  face  over  the 
body  of  the  lower  jaw,  at  the  anterior  inferior  angle  of  the  masseter  muscle,  where 
its  pulsation  may  readily  be  felt  and  it  may  be  compressed  against  the  bone. 
Thence  it  ascends  forward  across  the  cheek,  over  the  buccinator  muscle,  and  beneath 
the  platysma  myoides  muscle,  to  the  angle  of  the  mouth  ;  thence  to  the  side  of  the 
nose,  to  terminate  at  the  inner  canthus  of  the  eye  as  the  angular  artery.  Where 
the  artery  passes  over  the  lower  jaw  it  is  covered  by  the  platysma  myoides  muscle 
and  the  deep  fascia  ;  near  the  mouth  it  passes  beneath  the  zygomatici  major  and 
minor  and  the  risorius  muscle ;  and  along  the  side  of  the  nose  it  is  usually  covered 
by  the  levator  labii  superioris  alseque  nasi.  It  rests  successively  on  the  lower  jaw, 
the  buccinator,  and  the  levator  anguli  oris  muscle.  The  companion  vessel  of  the 
facial  artery,  the  facial  vein,  runs  in  an  almost  straight  line  from  the  inner  canthus 
of  the  eye  to  the  anterior  inferior  angle  of  the  masseter  muscle,  being  in  contact 


PLATE  CXXXII. 


Supraorbital  a 
Frontal  a. 


Orbital  a. 

Anterior  temporal  a. 

Posterior  temporal  a. 


Occipital  a. 


Posterior  auricular  a. 


Facial  a 

Inferior  Labial  a. 
Inferior  coronary  a. 
Superior  coronary  a. 


Superficial  temporal  a. 
Anterior  auricular  a. 
Middle  temporal  a. 
Parotid  gland 
Transverse  facial  a. 
Stenson's  duct 


ARTERIES  OF  SCALP  AND  FACE. 
504 


PLATE  CXXXIII. 


Malar  br.  of  facial  n.     Ttansverse  facial  a. 

Or(v-  I      Temporal  br. of  facia!  n. 


Temporal  br.  of  o  : 
Supraorbital 
Supraorbttal  a. 
Supratrochlear  n. 


Posterior  temporal  a. 

'-temporal  n. 


Occipital  a. 


Small  occipital  n. 


Posterior  auricular  a. 


Infratrochlear 
n, 

Artery  of  septum 
Lateral  nasal  a. 

Superior  coronary  a 

Inferior  coronary  a 

Inferior  labial  a 

Facial  a 

Facial  v. 


Anterior  auricular  a. 
Middle  temporal  a. 
Parotid  gland 
Supramaxillary  br.  of  facial  n. 
Stenson's  duct 


Buccal  br.of  facial   n. 
Infraorbital  br.of  facial  n, 
Socia  parotidis 


ARTERIES,  NERVES,  AND  MUSCLES  OF  SCALP  AND  FACE, 
505 


FACE.  on? 

with  tlio  facial  artery  at  thrse  points,  luit  dsc-where  above  and  external  to  it.  The 
artcrv  is  crossed  by  filaments  of  the  facial  nerve,  while  the  levator  lahii  superioris 
niu.-cle  separates  it  from  the  infra-orhital  nerve  liehind. 

Branches  of  the  Facial  Portion  of  the  Facial  Artery. — These  are  the  mus- 
cular, inferior  labial,  inferior  coronary,  superior  coronary,  lateralis  nasi,  and  angular. 

The  muscular  branches  are  directed  outward  to  supply  the  buccinator, 
niassetcr,  and  internal  pterygoid  muscles.  They  anastomose  with  the  masseteric 
and  buccal  brandies  of  the  internal  maxillary  and  with  the  infra-orbital  and 
transverse  facial  arteries. 

The  inferior  labial  artery  passes  inward  beneath  the  depressor  anguli  oris  to 
supply  the  muscles  and  integument  of  the  lower  lip  and  chin.  It  anastomoses  with 
the  inferior  coronary,  the  submental  branch  of  the  facial,  and  the  mental  branch  of 
the  inferior  dental  artery. 

The  inferior  coronary  artery  arises,  either  independently  or  in  common  with 
the  inferior  labial,  from  the  facial  artery  near  the  angle  of  the  mouth.  It  passes 
forward  and  inward  in  a  tortuous  manner  beneath  the  depressor  anguli  oris  toward 
the  angle  of  the  mouth,  then  pierces  the  orbicularis  oris,  and  continues  between 
it  and  the  mucous  membrane  along  the  free  margin  of  the  lower  lip.  It  anas- 
tomoses with  the  inferior  coronarj7  artery  of  the  opposite  side,  the  inferior  labial, 
and  the  mental  branch  of  the  inferior  dental  artery. 

The  superior  coronary  artery,  which  is  larger  and  takes  a  more  tortuous 
course  than  the  inferior  coronary,  arises  from  the  facial  artery  beneath  the  zygo- 
maticus  major  muscle.  It  pierces  the  orbicularis  oris,  and  runs  between  it  and  the 
mucous  membrane  along  the  free  margin  of  the  upper  lip  to  anastomose  with  the 
artery  of  the  opposite  side.  By  the  anastomosis  of  the  superior  and  inferior 
coronary  arteries  with  their  fellows  an  arterial  circle  is  formed,  which  surrounds 
the  mouth  and  can  be  felt  pulsating  on  the  internal  surface  of  the  lips  between 
one-fourth  and  one-half  of  an  inch  from  the  junction  of  the  skin  and  the  mucous 
membrane.  A  small  branch  to  the  ala  nasi  and  numerous  branches  to  the  labial 
glands  are  given  off  from  this  circle. 

The  artery  of  the  septum  of  the  nose  is  a  branch  of  the  superior  coronary. 
The  twigs  of  this  arteria  septum  narium  are  a  common  source  of  epistaxis  (nose- 
hired).  The  hemorrhage  from  the  branches  of  this  vessel  is  readily  controlled  by 
compression  of  the  artery  of  the  septum,  either  by  direct  backward  pressure  against 
the  upper  lip,  or  by  pressure  from  within  outward,  as  when  a  firm  pledget  of 
cotton,  paper,  or  other  substance  is  pushed  well  up  under  the  lip  so  as  to  put 
its  tissues  upon  the  stretch  and  occlude  the  lumen  of  the  artery.  This  is  a 
common  procedure  practised  by  the  laity.  Another  simple  method  is  that  of 
holding  the  cartilaginous  end  of  the  nose  between  the  thumb  and  finger. 


.     SURGICAL   .I.Y.r/'o.l/r. 

Harelip. — In  the  operation  tin-  harelip  the  bleeding  can  he  controlled  hy 
grasping  the  lip  between  the  ihunih  and  lot-Hinder.  In  introducing  the  harelip 
pin  or  suture,  it  must  be  passed  deep  enough  lo  go  hcneatli  the  divided  coronary 
artery.  Harelip  is  a  congenital  detonnity  consisting  of  one  or  more  lissttres  in  the 
upper  li]>,  the  result  of  arrested  development.  It  may  he  single  or  donhle,  the 
fissure  or  lissures  being  to  the  side  of  the  median  line  of  the  lip,  corresponding  to 
the  line  of  union  between  the  intermaxillary  and  the  superior  maxillarv  hone.  In 
double  harelip  the  intermaxillary  hone  is  often  displaced  forward.  Double  harelip 
is  frequently  associated  with  cleft  palate. 

The  lateralis  nasi  artery  arises  from  the  facial  artery  opposite  the  wing  of  the 
nose,  and  passes  forward  over  the  lower  part  of  the  nose  and  over  the  ala  ;  it 
supplies  the  side  and  dorsum  of  the  nose,  and  anastomoses  with  the  lateralis  nasi 
artery  of  the  opposite  side,  the  nasal  branch  of  the  ophthalmic,  the  infra-orbital, 
and  the  artery  of  the  septum. 

The  angular  artery,  the  terminal  part  of  the  facial,  passes  to  the  inner 
canthus  of  the  eye,  where  it  lies  on  the  nasal  side  of  the  lacrymal  sac  and  tendo 
oculi ;  it  anastomoses  with  the  nasal  branch  of  the  ophthalmic,  and  with  the  infra- 
orbital  artery,  and  supplies  branches  to  the  cheek.  In  opening  an  abscess  of  the 
lacrymal  sac  it  is  important  to  bear  in  mind  the  situation  of  this  artery  on  the 
inner  side  of  the  sac. 

Nervi  molles. — The  facial  artery  and  its  branches  are  surrounded  by  a 
minute  plexus  of  sympathetic  fibers  (nervi  molles)  not  demonstrable  maeroscopi- 
cally.  These  fibers  are  brandies  of  the  superior  cervical  ganglion  of  the  sympa- 
thetic, and  supply  the  walls  of  the  artery  and  its  branches;  they  furnish  the 
sympathetic  root  to  the  submaxillary  ganglion. 

Transverse  facial  artery. — Passing  transversely  across  the  face  between  the 
zygoma  and  the  duct  of  the  parotid  gland,  and  resting  upon  the  niasseter  muscle, 
is  the  transverse  facial  artery,  which  arises  from  the  temporal  artery  in  the 
substance  of  the  parotid  gland.  It  supplies  the  small,  often  detached,  part  of  the 
parotid  gland  (the  socia  parotidis)  in  relation  with  the  duct,  the  massctcr  and 
orbicularis  palpebrarum  muscles,  and  the  integument.  It  anastomoses  with  the 
infra-orbital,  facial,  and  masseteric  arteries.  It  is  accompanied  by  two  or  three 
branches  of  the  facial  nerve.  It  is  quite  small  except  when  it  supplies  those  parts 
which  usually  receive  blood  from  the  facial  artery.  It  occasionally  gives  off  the 
coronary  and  nasal  arteries,  the  facial  itself  being  small.  It  arises,  at  times,  from 
the  external  carotid  artery. 

The  facial  vein,  the  continuation  of  the  angular  vein,  and  formed  by  the  union 
of  the  frontal  and  supra-orbital  veins,  commences  at  the  inner  canthus  of  the  eye  and, 


PLATE  CXXXIV. 


Transverse  faci 


Front 


Supraorbit 


th  mastoid  v. 


VEINS  OF  SCALP    FACE,  AND  NECK, 
509 


FACE.  511 

:is  already  stated,  runs  in  an  almost  straight  line  to  the  anterior  inferior  angl 
the  massetcr  muscle,  where  it  comes  into  relation  with  the  outer  siile  of  the  facial 
artery.  In  its  course  across  the  face  it  lies  above  ami  to  the  outer  side  of  the 
artery,  passing  over  the  leva  tor  lahii  superioris,  beneath  the  zygornatic  muscles, 
and  over  the  parotid  duet,  the  buccinator  muscle,  the  anterior  inferior  angle  of  the 
masseter  muscle  and  masseterie  fascia,  and  the  body  of  the  lower  jaw.  Below  the 
jaw  it  is  joined  liy  the  anterior  branch  of  the  tcmporo-maxillary  vein,  and  empties 
into  the  internal  jugular  vein.  It  receives  veins  from  the  lower  eyelid  (the  inferior 
palpebral),  from  the  side  of  the  nose  (the  lateral  nasal),  from  the  orbital  vein,  and, 
heiieath  the  zygomaticus  major  muscle,  a  branch  (deep  facial)  from  the  ptervgoid 
plexus,  besides  muscular  branches  and  branches  corresponding  to  those  of  the 
facial  artery.  The  facial  vein — through  the  angular,  in  which  it  commences — 
communicates  freely  with  the  ophthalmic  vein,  and  thus  with  the  cavernous  sinus  ; 
and  it  also  communicates  with  the  cavernous  sinus,  through  the  deep  facial  vein 
with  the  pterygoid  plexus  of  veins,  which,  in  turn,  communicates  with  the  sinus 
by  means  of  small  veins  which  pass  through  the  foramen  ovale,  the  foramen  of 
Vesalius,  ami  the  middle  lacerated  foramen.  Owing  to  the  free  communication 
between  the  vein  and  the  cavernous  sinus,  the  latter  is  endangered  by  any  inflam- 
matory condition  of  the  facial  vein. 

Disease  involving  the  facial  vein. — The  facial  vein,  us  a  rule,  has  no 
valves  ;  it  will  therefore  be  understood  how  emholi  are  readily  carried  to  the 
internal  jugular  vein  and  thus  into  the  general  circulation.  Carbuncle  of  the  face 
may  prove  fatal  by  inducing  thrombosis  of  the  cerebral  sinuses  through  the  com- 
munications previously  described.  Any  deep  inflammation  of  tin1  face,  as  phleg- 
monous  erysipelas,  may  he  complicated  by  thrombosis  or  pyemia.  The  injec- 
tion of  facial  nevi  in  infants  may  result  in  death  from  thrombosis,  owing  to  the 
direct  communication  of  the  facial  with  the  internal  jugular  vein.  Pulmonary 
embolism  and  death  have  followed  the  injection  of  perchloric!  of  iron  for  nevoid 
growths  of  the  face.  In  arterio-venous  aneurysm  of  the  cavernous  sinus  arterial 
blood,  through  the  ophthalmic  and  angular  veins,  flows  through  the  facial  vein 
and  gives  rise  to  a  pulsating  varicose  condition  of  the  latter  vein  and  a  distinct 
thrill  and  bruit. 

Vascularity  of  the  face. — It  has  been  demonstrated  that  the  tissues  of  the 
face  are  very  vascular.  In  persons  exposed  to  cold,  or  in  those  addicted  to  strong 
drink,  the  very  small  vessels  of  the  skin,  especially  over  the  nose,  appear  per- 
manently injected  or  varicose.  Attention  has  been  called  to  the  fact  that  nevi 
and  various  forms  of  erectile  tumors  arc  common  about  the  face.  AVounds  of 
the  face,  while  they  bleed  freely,  heal  very  rapidly;  their  edges  should  be 
carefully  adjusted  as  soon  after  the  accident  as  possible.  "  Extensive  flaps  of 


:.]•_'  SURGICAL   ANATOMY. 

skin  which  have  been  torn  up  in  lacerated  wounds  of  the  face  often  retain  their 
vitality  in  almost  as  marked  a  manner  as  similar  flaps  torn  from  the  scalp" 
(Treves).  The  anastomose-  of  the  facial  artery  are  so  free  that  when  the  vessel  is 
divided,  both  ends  bleed  freely  and.  according  to  the  general  rule,  they  should 
both  be  tied. 

I)ISSI-:<TION. — I'pon  the  side  of  the  face  on  which  the  nuiseles  have  been 
exposed  the  appendages  of  the  eye, — including  the  eyelids,  eyebrows,  eyelashes, 
tarsal  cartilages,  conjunctiva,  and  lacrymal  caruncle. — the  parotid  gland,  and  the 
external  ear  should  be  carefully  dissected  before  turning  the  head  to  make  the 
dissection  of  the  nerves. 

The  eyebrow  is  a  prominent  arch  of  integument  connected  with  the  orbicu- 
laris  palpehrarutn,  corrugator  supercilii,  and  oceipito-frontalis  muscles.  It  is 
covered  by  numerous  short,  thick  hairs  which  surmount  the  upper  circumference 
of  the  orbit,  their  general  direction  being  outward,  though  they  interlace,  the 
upper  ones  curving  downward  and  the  lower  ones  upward.  They  serve  the  two- 
fold purpose  of  acting  as  a  shield  against  the  admission  of  foreign  bodies  to  the 
eye,  and  as  a  multiple  spring  buffer  reducing  somewhat  the  impact  of  blows  against 
the  brow,  thus  often  preventing  serious  wounds  of  the  skin  from  traumatism 
applied  against  the  sharp  supra-orbital  margin. 

The  eyelids  (palpebne)  are  two  movable  semilunar  curtains  placed  in  front 
of  each  eyeball  to  protect  that  exceedingly  delicate  and  important  organ.  Their 
free  edges  are  transverse  and  are  studded  with  hairs,  called  eyelashes.  The  upper 
lid  is  the  longer,  so  that  when  the  lids  are  closed,  their  margin  of  contact  lies  below 
the  center  of  the  eye.  The  upper  lid  is  also  more  freely  movable  ;  it  has  a  special 
muscle  to  raise  it — the  levator  palpebne  supcrinris.  The  interval  between  the 
open  eyelids  is  called  the  //'XXJ//Y/  ]i<i/i/r/>i-t/,-ii/n,  or  interpalpebral  slit.  At  the 
points  of  union  of  the  eyelids  are  the  e.rfrrituf  irml  iittfrim/  c<i////ii,  or  palpebral  com- 
missures. The  internal  canthus  is  the  larger;  within  it  is  a  triangular  space 
containing  a  depression,  the  lanix  lachrymalia,  and  an  elevation,  the  riirtniculn. 
[(u-liri/iini/i.i.  At  their  free  margins,  which  are  concave,  the  lids  are  thickest. 
At  their  inner  extremities  and  upon  their  free  surfaces  are  two  small  eleva- 
tions— the  papillic  lachri/vialiii,  in  the  center  of  which  are  small  openings  called 
the  /iniirfii  /iir/iri/iiiii/n/,  the  orifices  of  the  luri'i/nni!  niinilirn/i.  The  free  margins 
are  provided  in  front  with  eyelashes  and  with  orifices  of  sebaceous  and  modified 
sweat  glands ;  and,  behind,  with  small  openings — the  orifices  of  the  ducts  of  the 
Meibomian  glands.  That  portion  of  the  lids  internal  to  the  orifices  of  the 
lacrymal  canaliculi  is  devoid  of  eyelashes  and  Meibomian  glands.  When  the  eye- 
lids are  closed,  an  interval  exists  between  the  lids  and  the  eyeball  for  the 
inward  passage  of  the  tears.  Inflammation  of  the  ducts  opening  on  the  free 


PLATE  CXXXV. 


Lacrymal  punctum 
Lacrymal  caruncle, 


Lacrymal  punctum 

Plica  semilunaris 


Orifices  of  ducts  of 
meibomian  glands 


I 


33 


PALPEBRAL  FISSURE  AND  EYEBALL-EYELIDS  EVERTED, 
513 


FA  <'!•:.  515 

margin  of  the  eyelid,  which  usually  allecis  those  on  the  anterior  border,  con- 
stitutes a  stye. 

The  eyelashes  (cilia)  are  two  or  more  rows  of  short,  thick,  curved  hair.-,  lixed 
in  the  anterior  margin  of  the  free  hordrr  of  the  eyelids.  Tliey  are  longer  and 
more  numerous  in  the  upper  lid,  and  have  their  convexities  directed  downward, 
while  those  of  the  lower  lid  have  their  convexities  directed  upward.  They  protect 
the  eve  against  the  admission  of  dust  and  other  foreign  substances,  especially 
during  high  winds. 

The  conjunctiva. — Before  dissecting  the  eye-lid,  the  conjunctiva  and  the  lac- 
rynial  caruncle  should  be  examined.  The  conjunctiva  is  the  mucous  membrane 
which  covers  the  inner  surface  of  the  eyelids  and  the  anterior  part  of  the  eyeball. 
At  the  free  margin  of  the  lids  it  is  continuous  with  the  integument.  The  part 
covering  the  eyeball  is  in  relation  with  the  sclerotic  and  the  cornea.  The  conjunc- 
tiva consists  of  four  division-:  the  /iti//,/'/i,-nl.  the  portion  in  relation  with  the  eye- 
Lids;  the  reflected,  the  portion  between  the  eyelids  and  the  eyeball;  the  wlcrtitir, 
and  the  CIII-IKII/  portions.  The  lacrymal  ducts  (excretory  ducts  of  the  lacrymal 
gland)  empty  upon  the  free  surface  of  the  reflected  portion  of  the  conjunctiva. 
The  palpebral  portion  is  more  vascular  than  the  remaining  parts,  and  is  studded 
with  a  number  of  small  papilla1,  which,  when  enlarged  by  inflammation,  con- 
stitute the  disease  known  as  granular  lids,  though  this  condition  is  at  times  also 
due  to  true  granulations,  which  have  a  similar  origin.  The  conjunctiva  covering 
the  sclerotic  is  loosely  attached,  and  that  covering  the  cornea  is  very  thin,  consisting 
merely  of  an  epithelial  layer  which  is  very  adherent.  In  congestion  of  the  con- 
junctiva with  effusion  into  the  loose  subconjunctival  tissue  (chemosis)  the  mem- 
brane is  at  times  swollen  to  the  very  edge  of  the  cornea,  where  it  then  forms  a 
sharp  elevated  margin. 

The  caruncula  lachrymalis  is  a  small,  reddish  elevation  situated  at  the  inner 
canthus  in  the  lacus  lachrymalis.  It  consists  of  a  separated  portion  of  skin,  which 
presents  minute  hairs  upon  its  surface.  It  contains  connective  tissue,  a  small 
number  of  plain  and  striated  muscular  fibers  and  modified  sweat  glands,  as  well 
as  a  few  sebaceous  glands.  External  to  the  caruncle,  and  resting  upon  the  eyeball, 
is  a  vertical  triangular  fold  of  conjunctiva,  with  its  free  concave  margin  directed 
toward  the  cornea  ;  this  is  called  the  plica  semilunaris,  and  is  a  rudimentary  mem- 
brana  nictitans  (the  third  eyelid  in  birds).  Miiller  found  smooth  muscular  fibers 
in  this  fold,  and  in  some  of  the  domestic  animals  a  thin  plate  of  cartilage  lias  been 
discovered  in  it  (Gray). 

As  previously  stated,  the  conjunctiva  is  continuous  with  the  skin  at  the  free 
borders  of  the  lids.  It  is  also  continuous,  through  the  lacrymal  canaliculi, 
with  the  mucous  membrane  lining  the  lacrymal  sac,  the  nasal  duct,  and  the 


.->!<>  SURGICAL   ANATOMY. 

inferior  nieatus  of  the  nose.  In  tin-  loose subconjunctival  tissue-  there  are  not  infre- 
(|Ueiitly  seen,  (specially  in  elderly  person-,  small  yellowish  masses  of  fal,  called 
pingueculse. 

In  jjosi-ciinjuiictival  operations,  as  in  section  of  the  oqular  muscles,  the  con- 
junetiva  must  lie  cut.  Its  lax  attachment  to  the  sclera  is  now  of  advantage. 
for  a  loose  f»ld  is  readily  raised  with  the  forceps  and  incised  to  the  rc<iuired  extent. 
after  which  it  is  with  simple  facility  peeled  liaek  as  far  as  necessary. 

The  eyelids  are  composed  of  the  skin,  subcutaneous  tissue,  orbicularis  palpe- 
hrarum  muscle,  palpebral  ligaments,  orbito-taiv-al  ligaments,  the  iarsal  cartilages, 
Meibomian  glands,  vessels,  and  nerves,  and  conjunctiva.  The  upper  lid  contains, 
in  addition  to  the  structures  just  mentioned,  the  aponeurotic  insertion  of  the  leva- 
tor  palpehne  superioris  muscle.  The  skin  of  the  lids  and  the  orbicularis  palpe- 
lirarnm  muscle  have  already  lieen  descrilied. 

The  subcutaneous  areolar  tissue  of  the  eyelids  contains  no  fat.  Its  laxity 
accounts  for  the  extensive  ecclivmosis  after  comparatively  slight  tranmatism,  and 
for  the  early  appearance  of  pulfiness  of  the  eyelids  in  chronic  Hright's  disease. 

The  palpebral  ligaments  are  fibrous  hands  attaching  the  tarsal  cartilages  to 
the  outer  and  inner  margins  of  the  orbit.  The  external  ligament  is  undivided 
and  extends  from  the  malar  bone  to  the  outer  extremities  of  the  tarsal  cartilages. 
The  internal  ligament  (tendo  ociili)  extends  from  the  nasal  process  of  the  >nperi<>r 
maxilla  and  the  crest  of  the  lacrymal  bone  to  the  internal  extremities  of  the  Iarsal 
cartilages.  The  division  of  the  tendo  oculi  which  is  attached  to  the  nasal  proce-- 
of  the  superior  maxilla  passes  in  front  of  the  lacrymal  sac,  while  the  limb  attached 
to  the  crest  of  the  lacrymal  bone  passes  over  its  outer  wall. 

The  orbito-tarsal  ligaments  (palpebral  fascia?)  are  fibrous  membranes  continu- 
ous with  the  periosteum,  and  extend  from  the  superior  and  inferior  orbital  mar- 
gins to  the  tarsal  cartilages.  In  the  upper  lid  the  orbito-tarsal  ligament  fuses  with 
the  tendon  of  the  levator  palpebnc  superioris  muscle.  These  ligaments  prevent 
pus  in  the  subcutaneous  areolar  tissue  from  making  its  way  into  the  orbit,  and 
hence  are  called  the  septa  orbitale. 

The  tarsal  cartilages,  situated  in  the  free  margins  of  the  eyelids,  are  two 
plates  of  dense  connective  tissue.  They  are  thickest  at  their  free,  or  ciliary, 
margins,  and  give  support  and  shape  to  the  eyelids.  The  cartilage  of  the 
upper  lid  is  much  larger  than  that  of  the  lower,  and  gives  attachment  to  the 
aponeurosis  of  the  levator  palpebrse  superioris  muscle.  In  both  lids  the  attached 
margins  of  the  tarsal  cartilages  are  continuous  with  the  orbito-tarsal  ligaments. 

The  Meibomian  glands  are  sebaceous  glands  lodged  in  the  substance  of  the 
tarsal  cartilages,  and  number  between  twenty  and  thirty  in  the  upper  and  some- 
what less  in  the  lower  lid.  The  orifices  of  the  glands  open  on  the  free  borders  of 


PLATE  CXXXVI. 


Superior  portion  of  lacryma!  gland 

Inferior  portion  of  lacryinal  gland 

Levator  palpebrae  superioris  m 


Frontal  sinus 


Meibomian  glands 
Conjunctiva 

Orifices  of  ducts  of  meibomian  glands 
Orifices  of  lacrymal  ducts 


Tensor  tarsi  m. 
Lacrymal  sac 


Lacrymal  canaliculi 


LACRYMAL  APPARATUS  AND  MEIBOMIAN  GLANDS. 
517 


r.i  a-:.  519 

the  lids  behind  (lie  lashes.  Each  salami  consists  of  a  straight  tube  with  many 
short,  Lilind,  diverticula.  The  Meibomian  glands  secrete  a  sebaceous  material 
which  prevents  the  lids  from  adhering,  and  are  readily  distinguished  as  closely 
adjacent,  vertical,  parallel,  yellow  streaks  across  the  inner  surface-  of  the  lids. 
When  the  duet  of  one  of  these  glands  becomes  occluded,  a  retention  cyst,  similar 
to  a  wen,  is  formed. 

Non-striated  muscular  iihers  are  found  in  hoth  lids.  In  the  upper  lid  these 
fillers  originate  from  the  lower  surface  of  the  levator  palpebrffi  superioris ;  in  the 
lower  lid  they  arise  from  the  vicinity  of  the  inferior  oblique  muscle.  In  hoth 
lids  they  are  inserted  close  to  the  attached  border  of  the  tarsal  cartilage.  They 
arc  known  as  the  superior  and  inferior  palpebral  muscles  of  Midler. 

Hi, OOD  SUPPLY. — The  eyelids  receive  their  blood  supply  from  the  palpebral 
and  lacrymal  branches  of  the  ophthalmic  artery  and  from  small  branches  of  the 
temporal  and  transverse  facial  arteries.  The  palpebral  branches  of  the  ophthalmic, 
two  in  number,  arise  from  that  artery  near  the  pulley  of  the  superior  oblique 
muscle;  one  is  found  in  each  lid  and  runs  through  the  fibrous  tissue  layer  of  the 
lids  between  the  orbicularis  palpebrarum  muscle  and  the  tarsal  cartilages  near 
their  margins.  The  lacrymal  is  the  first  branch  of  the  ophthalmic  artery.  It 
accompanies  the  lacrymal  nerve  and  gives  oil'  palpebral  twigs  which  anastomose 
with  the  other  palpebral  arteries  to  form  the  tarsal  arches. 

The  ri'hix  i >f  (lie  ei/e!i/ls  are  larger  than  the  arteries,  and  outnumber  them. 
They  empty  into  the  frontal  and  angular  veins  at  the  inner  canthus,  and  into  the 
orbital  vein  at  the  outer  canthus.  Some  of  the  veins  of  the  lids  pass  between  and 
through  the  bundles  of  fibers  of  the  orbicularis  palpebrarum,  and  hence  in  many 
inflammatory  conditions  of  the  conjunctiva  and  cornea  in  children,  in  which 
prolonged  spasm  of  this  muscle  occurs,  the  lids  are  very  apt  to  become  edematous, 
from  interference  with  the  venous  How  (Fucho). 

NKUVK  SUPPLY. — The  nerve  supply  is  free.  The  nerves  to  the  palpebral 
portion  of  the  orbicularis  palpebrarum  muscle  arise  from  the -facial  nerve  and  enter 
the  lids  near  the  outer  canthus.  The  cutaneous  filaments  of  the  upper  lid  are 
obtained  from  the  lacrymal,  supra-orbital,  and  eupra-trochlear  nerve,  and  the 
lower  lid  derives  its  supply  from  the  infra-orbital  and  infra-trochlear  nerves. 
The  non-striated  muscular  tissue  of  the  lids  is  supplied  by  the  sympathetic  nerve. 

The  lymphatics  of  the  eyelids  pass  to  the  parotid  and  submaxillary  lymph 
glands. 

The  conjunctiva  has  been  described. 

The  levator  palpebrae  superioris  muscle  arises  from  the  under  surface  of 
the  lesser  wing  of  the  sphenoid  bone  above  the  optic  foramen ;  its  fibers  terminate 


•VJi>  SURGICAL   .\\.\TOMY. 

in  ;i  broad,  tliiu  aponeunMs  which  is  inserted  into  the  upper  border  of  the 
superior  tarsal  cartilage.  '1'his  muscle  runs  aliove  the  superior  red  us.  and  its 
uj>]ier  suri'aee  is  in  relation  witli  the  frontal  nerve  and  tin1  supra-orbital  artery. 

The  parotid  gland,  the  largest  of  the  saliva  ry  glands,  weighs  from  one-half  to 
one  ounce.  It  is  situated  on  the  side  of  the  face,  and  extends  as  high  as  the 
xygoma  and  below  the  level  of  the  angle  of  the  lower  jaw.  It  covers  about  one- 
third  of  the  masseter  muscle,  and  extends  backward  to  the  external  auditory 
ineatns,  the  masloid  process,  and  the  sterno-niastoid  muscle.  It  is  lodged  in  tin- 
space  between  the  ranius  of  the  lower  jaw  and  the  niastoid  process.  This  spact — 
known  also  as  the  bed  of  the  parotid  gland — can  be  increased  in  si/e  by  extending, 
and  diminished  by  Hexing,  the  head.  With  the  mouth  wide  open — in  which  posi- 
tion the  angle  of  the  jaw  is  carried  backward  and  the  condyle  forward — the  width 
of  the  space  is  diminished  below,  but  increased  above.  The  si/e  of  the  space  ig 
influenced  by  the  age  of  the  individual.  In  the  infant,  owing  to  the  obliquity  of 
the  ranius  and  the  absence  of  the  angle  of  the  lower  jaw,  it  is  broader,  in  propor- 
tion, below.  Ill  advanced  age,  when  the  teeth  have  fallen  out.  thus  allowing 
the  angle  of  the  lower  jaw  to  project  forward,  the  space  is  broader  below.  When 
operating  in  this  space  these  facts  should  be  kept  in  mind,  as  it  may  be  necessary 
to  take  advantage  of  them.  The  gland  has  three  large  processes  or  lobes :  one. 
the  ijli-nniil  lulu-,  extends  upward  into  the  posterior  part  of  the  glenoid  cavity  of 
the  temporal  bone  which  it  occupies;  another,  the  ji/fri/f/oiil  /<,/,<;  extends  forward 
beneath  the  minus  of  the  lower  jaw,  between  the  external  and  internal  pterygoid 
muscles;  the  third  process,  the  car»ti<l  lube,  passes  behind  the  styloid  process 
and  beneath  the  mastoid  process  and  the  sterno-mastoid  muscle,  coming  in 
contact  with  the  internal  jugular  vein  and  the  internal  carotid  artery.  From 
the  relation  which  the  carotid  lobe  holds  to  the  internal  jugular  vein,  it  follows 
that  swelling  of  the  gland,  as  in  mumps,  may  cause  passive  congestion  of  the 
brain  by  compression  of  that  vein.  The  anterior  margin  of  the  parotid  gland 
overlaps  the  masseter  muscle,  and  a  detached  portion  of  the  gland  (win  jmrtititlix) 
lies  over  that  muscle  in  relation  with  the  upper  border  of  Stenson's  duct. 
From  the  position  which  the  parotid  gland  holds  with  reference  to  the  teinporo- 
maxillary  articulation  it  follows  that,  in  inflammation  of  the  gland,  movement  of 
the  articulation  is  attended  by  pain  :  the  extent  to  which  the  lower  jaw  can  be 
depressed  under  these  circumstances  is  dependent  upon  the  amount  of  swelling. 

Parotid  fascia. — The  parotid  gland  is  covered  by  a  dense  and  strong  layer  of 
fascia — a  prolongation  of  the  superficial  layer  of  the  deep  cervical  fascia,  and 
called  the  parotid  fascia.  It  is  attached  aliove  to  the  zygoma,  and  is  continuous 
in  front  with  the  fascia  covering  the  masseter  muscle.  From  the  parotid  fascia 
numerous  processes  are  sent  into  the  substance  of  the  gland  to  support  its  lobules. 


PACK.  ".21 

The  deep  fascia  of  the  neck  also  sends  beneath  Ihe  gland  a  process  continuous  with 
tlie  stylo-maxillary  ligament,  which  separates  the  parotid  from  the  submaxillary 
aland.  Tlie  fil irons  envelop  of  the  parotid  inland  is  incomplete  above  and  in 
front,  where  its  cavity  is  in  communication  with  the  pterygo-maxillary  region.  In 
parotid  aliscess  the  pus  may.  on  account  of  this  gap  in  the  fascia!  envelop, 
extend  into  the  pterygo-maxillary  region,  and  by  way  of  the  latter  into  the  tem- 
poral fossa,  or  to  the  side  of  tin1  pharynx,  meeting  with  less  resistance  in  taking 
either  of  these  directions  than  in  attempting  to  reach  the  surface.  The  abscess 
may,  however,  extend  into  the  neck  by  ulcerating  through  the  layer  of  fascia 
beneath  the  gland.  Many  cases  of  retro-pharyngeal  abscess  are  attended  l>y 
swelling  in  the  parotid  region,  lietro-pharyngeal  growths — as,  for  example, 
sarcomata,  when  they  have  attained  any  si/.e — -cause  bulging  of  the  parotid  region  : 
and,  conversely,  tumors  of  the  parotid  may  bulge  into  the  pharynx.  The  severe 
pain  in  a  rapidly  growing  tumor  or  abscess  of  the  gland  is  due  to  the  density  of 
the  fascia  covering  it.  This,  too,  makes  it  difficult  to  detect  fluctuation  early.  It 
also  explains  why  the  pus  in  a  parotid  abscess  is  so  slow  to  find  its  way  to  the 
surface,  and  why  an  early  opening  should  be  made.  The  intimate  relation 
existing  between  the  parotid  gland,  the  external  auditory  nieatus,  and  the 
temporo-maxillary  articulation  is  to  be  borne  in  mind,  as  a  parotid  abscess  may 
open  into  the  meatus  or  cause  involvement  of  the  joint, 

Purulent  meningitis  and  thrombosis  of  the  cranial  sinuses  may  be  caused 
when  pus  finds  its  way  through  the  foramina  at  the  base  of  the  skull. 

The  sensory  nerves  supplying  the  parotid  gland  are  the  auriculo-temporal 
branch  of  the  inferior  maxillary  nerve,  the  great  auricular  branch  of  the  cervical 
plexus,  the  facial  nerve,  and  branches  from  the  carotid  plexus  of  the  sympathetic 
nerve.  In  painful  affections  of  the  gland  the  pain  is  apt  to  be  referred  to  the  areas 
of  distribution  of  these  nerves. 

The  parotid  lymphatic  glands. — Lying  upon  the  surface  of  the  parotid  gland 
(in  front  of  the  cartilage  of  the  ear,  and  close  to  the  root  of  the  zygoma)  are  one 
or  more  superficial  lymphatic  glands,  enlargement  of  which  must  not  be  mistaken 
for  a  similar  condition  of  the  parotid  gland  itself. 

Contents  of  the  parotid  gland. — The  parotid  gland  is  important,  not  only  on 
account  of  its  function,  of  the  position  which  it  occupies,  and  of  the  relation  it  bears 
to  the  surrounding  parts,  but  also  because  important  structures  are  found  in  it. 
These  structures  are,  from  without  inward  :  The  facial  nerve,  passing  from  behind 
forward  ;  the  temporo-maxillary,  superficial  temporal,  internal  maxillary,  and 
posterior  auricular  veins;  the  commencement  of  the  external  jugular  vein  ;  the 
external  carotid  artery  which  supplies  branches  to  the  gland  and  divides  at  the 
neck  of  the  lower  jaw  into  its  two  terminal  branches — the  temporal  and  internal 


'>•!•!  SURGICAL  ANATOMY. 

maxillary  arteries;  the  terminal  part  of  the  great  auricular  nerve:  and  one  or  two 
lymphatic  glands.  The  posterior  auricular  hranch  of  the  external  carotid  artery 
and  the  transverse  facial  hranch  of  the  temporal  artery  arise  in  the  substance  of 
I  he  inland. 

The  parotid  gland  is  separated  from  the  internal  carotid  artery,  from  the 
internal  jugular  vein,  and  from  the  pneumogastric.  glosso-pharyngval,  and  hypo- 
glossal  nerves  hy  a  thin  layer  of  fascia;  therefore  in  stab  wounds  of  the  parotid 
region  involving  one  of  the  two  carotid  arteries  it  may  be  difficult,  at  first,  to  tell 
which  of  the  two  vessels  has  been  wounded. 

From  an  anatomic  point  of  view  it  is  difficult  to  sec  how  complete  removal 
of  the  parotid  gland  is  possible,  yet  the  operation  has  been  done  so  many  times  by 
skilful  surgeons  that  there  is  no  question  of  its  feasibility.  Doubtless,  as  long  ago 
suggested  by  Fiihrer,  when  the  gland  becomes  the  site  of  a  neoplasm  it  becomes 
more  compact,  its  processes  being  rounded  off,  as  it  were,  and  lifted  away  from  the 
surrounding  structure-;. 

Complete  removal  of  the  parotid  gland  results  in  paralysis  of  the  muscles  of 
expression,  for  it  is  impossible  to  avoid  dividing  the  facial  nerve.  The  author  has 
seen  a  growth  of  the  overlying  lymphatic  gland  cause  facial  paralysis  from  pressure, 
and  thus  so  closely  simulate  a  parotid  neoplasm  as  to  be  pronounced  a  tumor  of 
the  parotid  gland  ;  but  upon  the  removal  of  the  growth  the  parotid  gland  was  seen 
to  occupy  the  bottom  of  the  wound,  and  to  be  in  a  very  much  atrophied  condition. 

Socia  parotidis. — That  portion  of  the  parotid  gland  resting  upon  the  masseter 
muscle  above  the  parotid  duct  (Stenson's  duct),  and  quite  separate  from  the  gland 
proper,  is  known  as  the  socia  parotidis.  Its  duct  empties  into  Stenson's  duet. 

Stenson's  duct. — Running  about  one  finger's  breadth  below  the  zygoma,  or  in 
a  line  drawn  from  the  lower  margin  of  the  concha  to  a  point  midway  between  the 
free  margin  of  the  upper  lip  and  the  ala  of  the  nose,  is  the  duct  of  the  parotid 
(Stenson's  duet).  It  is  about  two  inches  in  length  by  one-eighth  of  an  inch  in 
diameter,  being  narrowest  at  its  point  of  communication  with  the  mouth.  It  lies 
between  the  transverse  facial  artery  above  and  the  buccal  branch  of  the  facial 
nerve  below.  The  duct  runs  over  the  masseter  muscle,  turning  abruptly  inward 
at  its  anterior  border,  passes  through  the  mass  of  fat  overlying  the  buccinator 
muscle  and  beneath  the  facial  vein,  and  pierces  the  buccinator  muscle  to  open 
into  the  mouth  opposite  the  crown  of  the  second  molar  tooth  of  the  upper  jaw. 
The  turn  of  the  duct  around  the  anterior  border  of  the  masseter  muscle  must  be 
borne  in  mind  when  passing  a  probe  into  the  duct  from  the  mouth.  In  opening 
a  parotid  abscess  the  incision  should  be  horizontal,  and  should  be  made  below  the 
line  of  the  duct  and  in  front  of  the  posterior  border  of  the  ramus  of  the  lower 
jaw.  Failure  to  observe  this  caution  may  result  in  section  of  the  duct,  with 


r.ics. 

resulting  fistula  ('salivary  fistula).  It  is  also  advisable  to  take  every  precaution 
against  cutting  through  the  gland  tissue  in  opening  a  jiarotid  aliseess,  for  these 
collections  of  pus,  like  those  of  the  mamma-,  generally  atl'ect  the  connective  tissue 
of  the  gland  and  not  its  snhstaiice  or  parenchyma. 

Stenson's  duct  mav  he  divided  into  a  niassrteric  and  a  bnccal  portion.  The 
i,ttixx/ft  /•/(•  /mi -tin a  rests  upon  the  ma>seter  musele  and  the  /nnrn/  /mrt  exh-nd>  from 
the  anterior  horder  of  the  masseter  muscle  to  the  termination  of  the  duct  in 
the  mucous  memhrane  of  the  check.  Fistula.1  of  the  masseteric  part  are  closed 
with  difficulty,  whereas  fistula'  of  the  hnccal  portion  are  remedied  hy  making  an 
opening  from  the  duct  into  the  mouth  on  the  proximal  side  of  the  fistula.  The 
author  has  successfully  treated  listula1  of  the  buccal  portion  hy  exposing  the  duct 
through  an  incision  in  the  cheek,  dividing  the  duct  at  the  proximal  side  of  the 
fistula,  freeing  the  duct  from  the  surrounding  tissues,  and  stitching  the  divided 
end  to  the  margins  of  an  opening  made  in  the  mucous  membrane  of  the  mouth. 

DISSECTION. — Before  turning  over  the  head  to  make  the  dissection  of  the  oppo- 
site side  of  the  face,  the  parotid  gland  should  he  removed  entire;  this  operation  will 
convey  an  approximate  idea  of  the  difficulties  which  would  attend  the  removal  of 
the  gland  in  the  living  subject.  The  masseter  muscle  should  then  be  exposed  and 
(lie  external  ear  dissected.  In  exposing  the  parotid  gland,  its  fascial  covering  is 
seen  to  be  continuous  anteriorly  with  the  fascia  covering  the  masseter  muscle,  and, 
therefore,  the  parotid  and  masseteric  fascia:  are  practically  one.  These  fascia-  are 
derived  from  the  superficial  layer  of  the  deep  cervical  fascia,  which  is  continued 
upward  over  the  body  of  the  lower  jaw  and  attached  above  to  the  zygoma.  By 
displacing  the  parotid  gland  forward  and  removing  the  fascia  covering  that  portion 
of  the  masseter  muscle  in  advance  of  the  gland,  the  muscle  itself  is  exposed. 

The  masseter,  the  most  superficial  of  the  muscles  of  mastication,  is  of  quad- 
rate form,  and  arises  as  two  portions — a  large,  tendinous,  superficial  layer,  and  a 
small,  Ik-shy,  deep  layer.  The  superficial  sheet  arises  from  the  anterior  two-thirds 
of  the  lower  border  of  the  zygomatie  arch  and  from  the  lower  border  of  the  malar 
hone  ;  its  fibers  pass  downward  and  backward  to  he  inserted  into  the  outer  surface 
of  the  angle  and  lower  portion  of  the  ramus  of  the  lower  jaw.  The  deep  sheet 
arises  from  the  posterior  third  of  the  lower  horder  and  all  of  the  inner  surface 
of  the  zygoma  ;  it  passes  downward  and  forward  to  be  inserted  into  the  upper 
half  of  the  ramus  and  the  outer  surface- of  the  coronoid  process  of  the  lower  jaw. 
The  posterior  portion  of  the  muscle  is  concealed  by  the  parotid  gland.  In  relation 
with  the  superficial  surface  of  the  muscle  are  the  orbicularis  palpebrarum,  the 
zygomatici  major  and  minor,  and  the  platysma  myoides  muscle,  the  anterior 
margin  of  the  parotid  gland,  Stenson's  duct,  the  transverse  facial  vessels,  branches 
of  the  facial  nerve,  and,  at  its  anterior  inferior  angle,  the  facial  vein.  In  relation 


•V_M  SURGICAL   AXATO-UY. 

witli  its  dec])  surface  are  llic  buccal  pad  of  fat.  the  l)iiccin;(t(ir  iind  a  small  part  of 
the  temporal  muscle,  the  masseteric  arterv  and  nerve,  and  the  minus  of  the  jaw. 

l)L(Kii)  SriTi.v. — From  the  masseteric  brunch  <>f  the  internal  maxillary,  the 
transverse  facial,  and  the  facial  artery. 

NKKVK  Sri'i'i.v. — From  the  masseteric  nerve,  a  brunch  of  the  interior  maxil- 
lary division  of  the  trifacial  nerve. 

ACTION. — It  raises  the  lower  jaw,  us  in  mastication. 

The  External  Ear  consiMs  of  the  pinna,  or  auricle,  and  of  the  tube  leading  to 
the  tympanic  membrane — the  external  auditory  cunul.  The  pinna  collects  the 
vibrations  of  sound,  and  the  canal  conveys  them  to  the  tympanum. 

The  pinna,  or  auricle,  is  pyriform  in  shape,  with  its  concave  surface  diivcicd 
outward  and  slightly  forward,  and  consiMs  of  a  layer  of  yellow  fibre-cartilage 
having  an  uneven  surface  covered  with  integument.  It  is  attached  to  the  com- 
mencement of  the  external  auditory  meatus,  and  consists  of  various  elevations  and 
depressions,  each  elevation  having  a  corresponding  depression  on  its  opposite 
surface.  The  deep  hollow  in  its  center,  which  is  wide  above  and  narrow  below,  is 
called  the  concJm.  The  concha  leads  to  the  commencement  of  the  external  audi- 
tory meatus.  and  is  partly  divided  into  two  by  the  beginning  of  the  helix.  The 
liclix  passes  upward,  forms  the  rim  of  the  pinna,  and  terminates  behind  in  the 
Io/ml<;  which  is  the  lowest  portion  of  the  auricle  and  consists  of  fatty  and  areolar 
tissue.  Internal  to  the  helix  is  the  depression  called  the  fossa  of  tin-  li<li.c.  or 
Kcn/>hoid  fossa.  Internal  to  the  fossa  of  the  helix  is  the  ridge  bounding  the  concha 
behind  and  above.  This  ridge  is  called  the  (inllirfl.,- :  it  begins  above  the  lobule, 
at  a  small  prominence,  the  cintltr<ii/iit<.  and  bifurcate-  at  the  upper  part  of  the 
auricle,  embracing  a  small  triangular  depression— the  f</xx<i  <>f  tin-  iniflidi.c.  In 
front  of  the  concha  and  projecting  backward  over  the  orifice  of  the  external  audi- 
tory meatus  is  the  tragus.  Between  the  trugus  and  antitragus  is  a  notch — the 
incisuni  intertragica. 

DISSECTION. — The  integument  should  be  removed  from  the  pinna,  when  the 
small  and  rudimentary  muscles  and  the  cartilage  will  be  exposed. 

The  integument  of  the  pinna  is  thin  and  delicate.  It  contains  sebaceous 
glands  which  are  largest  in  the  concha,  and  here  the  ducts  of  the  glands  often 
become  filled  with  foreign  matter,  giving  rise  to  the  so-called  comedones. 

Upon  the  posterior  aspect  of  the  auricle  the  integument  is  less  firmly  attached 
to  the  underlying  parts  than  elsewhere,  consequently  inflammatory  swellings,  as  in 
erysipelas,  are  most  marked  in  this  situation. 

Extravasations  of  blood  beneath  the  skin  are  not  uncommonly  seen  as  the 
result  of  blows  upon  the  ear ;  these  so-called  othematomuta  have  been  most  often 
observed  in  insane  persons  and  in  prize-fighters.  According  to  Yirchow  and 


PLATE  CXXXVII. 


Heli 


Fossa  of  helix 


Darwin's  tubercle 


Antihelix 


Concha 


Antitragus 

Lobule 


Fossa  of  antihelix 


Tragus 


isura  intertragica 


PINNA 
525 


PLATE  CXXXVIII, 


Helix 


Darwin's  tubercle 


;  major  m. 


Obliquus  auris  m. 


Tragicus  m. 
Fibrous  band 
Helicis  minor  m . 
Antitragicus  m. 
Processus  caudatus 


Transvesus  auris  m. 


Fissure  of  Santorini 


INTRINSIC  MUSCLES  OF  PINNA. 
527 


FACE.  r,-_><) 

Ludwig  Meyer,  degenerative  changes  in  the  blood-vessels  and  cartilage  favor  the 
occurrence  of  such  extravasations.  Cicatricial  contractions  may  cause  deformity 
of  the  pinna  alter  the  absorption  or  evacuation  of  such  hematuinata.  I'nder 
the  integument  of  tlie  lobule  polity  deposit-  (tophi)  arc  sometimes  found. 

The  Muscles  which  move  the  cartilage  of  the  ear  as  a  whole,  three1  in  number, 
have  heel)  described  under  the  dissection  of  the  scalp.  The  muscles  proper  <>f  the 
auricle,  which  extend  from  one  part  of  the  cartilage  to  another,  are  six  in  number 
— namely,  the  muscle  of  the  trains,  the  muscle  of  the  antitragus,  the  small 
muscle  of  the  helix,  the  large  muscle  of  the  helix,  the  transverse  muscle  of  the 
auricle,  and  the  oblique  muscle  of  the  auricle. 

The  tragicus,  the  muscle  of  the  trains,  is  situated  upon  the  outer  surface  of 
the  trains. 

The  antitragicus,  the  muscle  of  the  antitragus.  arises  from  the  outer  part  of 
the  antitragus  :  its  libers  pass  upward  and  are  inserted  into  the  posterior  extremity 
of  the  helix. 

The  helicis  minor,  the  small  muscle  of  the  helix,  is  attached  to  the  commence- 
ment of  the  helix  and  extends  into  the  concha.  This  muscle  is  sometimes  absent. 

The  helicis  major,  the  large  muscle  of  the  helix,  is  situated  upon  the  anterior 
margin  of  the  helix  :  it  arises  above  the  small  muscle  and  is  inserted  into  the  front 
of  the  helix,  where  it  begins  to  curve  backward. 

The  transversus  auris,  the  transverse  muscle  of  the  auricle,  is  situated  on 
the  back  of  the  auricle  in  the  depression  between  the  helix  and  the  convexity  of 
the  concha  ;  it  arises  from  the  convexity  of  the  concha  and  is  inserted  into  the  back 
of  the  helix. 

The  obliquus  auris,  the  oblique  muscle  of  the  auricle,  extends  from  the  upper 
back  part  of  the  concha  to  the  convexity  immediately  above  it. 

NERVE  SUPPLY. — The  pinna  derives  its  nerve  supply  from  the  auriculo- 
temporal,  the  posterior  auricular,  the  auricular  branch  of  the  pneumogastric 
(Arnold's  nerve),  the  occipitalis  minor,  and  the  auricularis  magnus  nerve. 

ACTION. — The  muscles  of  the  helix  assist  those  of  the  tragus  and  antitragus 
in  retarding  the  passage  of  sound  to  the  meatus. 

BLOOD  SUPPLY. — The  pinna  is  well  supplied  with  freely  anastomosing  vessels — 
branches  of  the  posterior  auricular,  temporal,  and  occipital  arteries.  The  veins 
accompany  the  corresponding  arteries. 

The  numerous  lymphatics  empty  into  the  pre-auricular  glands  and  into  those 
situated  upon  the  insertion  of  the  sterno-mastoid  muscle. 

The  cartilage  of  the  pinna  is  a  single  piece,  and  presents  the  irregularities 
characteristic  of  the  external  ear.     It  is  prolonged  inward  in  the  shape  of  a  tube 
34 


SURGICAL  ANATOMY. 

wliicli  forms  the  outer  part  of  the  external  auditory  nicatus  ;  it  is  wanting  IH  tween 
the  trains  and  the  commencement  of  the  helix,  the  interval  between  them  being 
occupied  by  lihrous  tissue.  Where  the  helix  makes  its  lirst  liend,  at  the  front  part 
of  the  pinna,  is  a  conic  projection  of  the  cartilage — the  process  of  the  helix.  At 
the  highest  part  of  the  helix  there  is  not  infrequently  to  he  seen  another  conic 
projection,  to  which  Darwin  tirst  called  attention;  he  regards  it  as  the  represen- 
tative of  the  extreme  tip  of  the  pinna  of  some  of  the  lower  animals.  At  certain 
places  the  cartilage  is  incomplete;  these  gaps  are  known  as  fissures,  and  are 
located  as  follows :  at  the  anterior  part  of  the  pinna,  behind  the  process  of  the 
helix  (fissure  of  the  helix) ;  on  the  surface  of  the  tragtis  ;  and  at  the  lower  part  of  the 
anthelix.  In  the  piece  of  cartilage  which  forms  the  outer  part  of  the  meatus  are 
two  fissures — the  //'.-.-X///VN  i if  Suii/nriiii.  The  pinna  is  attached  anteriorly  to  the 
root  of  the  x.ygoma  and  posteriorly  to  the  mastoid  process  by  hands  of  fibrous 
tissue  ;  iii  addition,  there  are  various  intrinsic  ligaments,  uniting  the  different  parts. 

DISSECTION. — Turn  the  head  to  the  opposite  side,  fix  it  with  hooks,  and  work 
out  the  facial  nerve  and  the  branches  of  the  trifacial  nerve  which  make  their  exit 
upon  the  face.  Expose  the  facial  nerve  by  a  longitudinal  incision  carried  into  the 
substance  of  the  parotid  gland  in  front  of  the  lobe  of  the  ear,  cutting  away  a  little 
of  the  gland  with  each  movement  of  the  knife  until  the  nerve  is  seen,  when  it  can 
be  traced  both  backward  and  forward. 

The  facial  nerve  (the  seventh  cranial)  is  the  motor  nerve  of  the  face;  it 
consists  of  three  portions — the  intra-cranial,  the  temporal,  and  the  facial.  The 
facial  portion,  that  which  concerns  us  in  this  dissection,  supplies  all  the  muscles  of 
expression  and  the  platysma,  the  buccinator,  the  occipito-frontalis,  the  attrahens, 
attolens,  and  retrahens  aurem,  the  posterior  belly  of  the  digastric,  and  the  stylo- 
hyoid. 

A  line  drawn  from  the  anterior  border  of  the  mastoid  process  opposite  the 
li.-iM'  of  the  lobule  of  the  ear  downward  and  forward  across  the  face  for  about  one 
inch  will  represent  the  course  of  the  facial  portion  of  the  trunk  of  the  nerve. 

COURSE. — It  leaves  the  cranial  cavity  through  the  internal  auditory  meatus  in 
company  with  the  auditory  nerve,  the  pars  intermedia  of  Wrisberg,  and  the 
auditory  artery.  Reaching  the  bottom  of  the  internal  auditory  meatus  it  enters 
the  facial  canal,  or  aqueductus  Fallopii  of  the  temporal  bone,  from  which  it  makes 
its  exit  by  way  of  the  stylo-mastoid  foramen.  Passing  downward  and  forward 
from  the  foramen  it  enters  the  parotid  gland,  crosses  the  external  carotid  artery, 
gives  off  a  posterior  auricular,  a  digastric,  and  a  stylo-hvoid  branch,  and  terminates 
in  two  divisions — the  temporo-faeial  and  the  cervico-facial. 

The  posterior  auricular  nerve,  the  first  extra-cranial  branch,  passes  upward 
in  the  groove  between  the  ear  and  the  mastoid  process,  communicates  with  the 


PLATE  CXXXIX. 


Temporal  br.  of  orbital  n 
Supraorbi: 
Supratrochlear 


Malar  br.  of  facial  n. 


Temporal  br.  of  facial  n. 


Great  occipital  n. 


Small  occipital  n. 


'Auriculo-temporal  n. 
Infraorbital  br.  of  facial  n. 

Great  auricular  n. 


Supramaxillary  br.  of  facial  n. 
Buccal  br.  of  facial  n. 


Infraorbital  br.  of  superior  maxillary  n. 


Mental  n. 
Infratrochlear  n. 


Nasal  n" 


NERVES  OF  SCALP  AND  FACIAL  NERVE. 
531 


l-'A  <•/•:.  533 

auricular  lirancli  of  the  pneumogastrio  and  the  great  auricular  branch  of  the 
cervical  plexus,  and  divides  into  an  auricular  and  an  occipital  branch.  The 
auricular  branch  supplies  the  atlolens  and  ivtrahcns  aui'eni  muscles.  The 
occipital  brancli  passes  along  the  superior  curved  line  of  the  occipital  bone, 
supplies  the  occipitalis  muscle,  and  communicates  with  the  small  occipital  branch 
of  the  cervical  plexus. 

The  digastric  branch  supplies  the  posterior  belly  of  the  digastric  muscle,  and 
communicates,  by  a  twig  which  usually  .perforates  that  muscle,  with  the  glosso- 
pharyngeal  nerve. 

The  stylo-hyoid  branch  is  longer  than  the  digastric  ;  it  enters  the  stylo-hyoid 
muscle  about  its  middle,  and  communicates  with  filaments  of  the  sympathetic 
nerve  on  the  external  carotid  artery. 

The  temporo-facial,  tlic  larger  of  the  two  terminal  divisions,  runs  obliquely 
upward  and  forward  through  the  substance  of  the  parotid  gland,  crosses  the 
external  carotid  artery  and  the  temporo-maxillary  vein,  and  breaks  up  into  the 
temporal,  malar,  and  infra-orbital  branches.  It  communicates  with  the  auriculo- 
temporal  nerve.  The  ti-iii/inrnl  l>i-<inrli<x  ascend  obliquely  over  the  /ygomatic 
arch  to  supply  the  tensor  tarsi,  the  orbicularis  palpebrarum,  the  corrugator 
supercilii,,  the  froutalis,  and  the  attolens  and  attrahens  aurem  muscles,  and  to 
communicate  with  the  supra-orbital,  the  lacrymal,  and  the  auricula-temporal 
nerve,  and  with  the  temporo-malar  branch  of  the  superior  maxillary  nerve. 

The  malar  branches  run  across  the  malar  bone  to  the  outer  angle  of  the 
orbit  to  supply  the  orbicularis  palpebrarum  muscle,  and  communicate  with  the 
lacrymal  and  the  supra-orbital  nerve  and  with  the  infra-orbital  and  temporo- 
malar  branches  of  the  superior  maxillary  nerve.  The  infra-orbital,  the  largest 
branch,  gives  off  a  superficial  and  a  deep  set  of  branches,  which  pass  transversely 
forward  over  the  masseter  and  beneath  the  zygomatic  muscles  to  supply  the 
zygomatic  muscles,  the  elevators  of  the  upper  lip,  the  muscles  of  the  nose,  and 
the  orbicularis  oris  muscle.  The  superficial  branches  communicate  with  the  nasal 
and  infra-trochlear  nerves  which  are  derived  from  the  ophthalmic  division  of  the 
trifacial  nerve.  The  deep  branches  form  a  loop  with  the  buccal  branch  of  the 
cervico-facial  division,  and  pass  beneath  the  levator  labii  superioris  muscle,  where 
they  unite  with  the  infra-orbital  branch  of  the  superior  maxillary  nerve,  forming 
the  infra-orbital  plexus. 

The  cervico-facial,  the  smaller  of  the  two  terminal  divisions  of  the  facial 
nerve,  is  joined  by  a  branch  of  the  great  auricular  nerve  while  in  the  substance  of 
the  parotid  gland.  It  passes  obliquely  downward  toward  the  angle  of  the  lower 
jaw,  crosses  the  external  carotid  artery  and  the  temporo-maxillary  vein,  and  divides 
into  buccal,  supra-maxillary,  and  infra-maxillary  branches.  The  buccal  branches 


•V!4  SURGICAL   ANATOMY. 

pass  forward  over  the  masseter  and  buccinator  muscles  below  Stenson's  duel,  to  the 
angle  of  the  inoiitli,  to  supply  the  huceiiiator  and  orhicularis  uris  muscles,  and 
cdiinnuiiicate  with  the  ini'ra-orhital  nerve,  the  infra-orhital  hranches  oi'  the 
temporo-faeial  hraiieh.  and  the  long  huccal  hranch  of  the  inl'erior  maxillary  nerve. 
The  huceal  hranch  of  the  facial  nerve  and  the  long  huccal  hranch  of  the  inferior 
maxillary  nerve  form  a  plexus  over  the  hiiccinator  muscle  and  the  facial  vein. 
The  suprcwmaxillary  branch  passes  downward  and  forward  over  the  niasseter  muscle 
and  the  facial  artery,  and  heneath  the  platysma  myoides  and  the  depressor  muscles 
of  the  lower  lip.  It  supplies  the  muscles  of  the  lower  lip.  the  risorius,  and  the 
levator  menti,  and  communicates  with  the  huccal  branch  of  the  facial  and  the 
mental  hranch  of  the  inferior  dental  nerve.  The  !i(l'i-ii-iiiiu-il!>ii-i/  In-nni-li  emerges 
from  the  lower  horder  of  the  ]>arotiil  gland  in  front  of  the  external  jugular  vein 
and  passes  downward  and  forward  toward  the  sternum  heneath  the  platysma 
myoides  muscle,  which  it  supplies.  It  communicates  with  the  great  auricular  and 
superficial  cervical  nerves — hrauehes  of  the  cervical  plexus.  The  infra-maxillary 
hranch  can  he  traced  when  dissecting  the  superficial  fascia  of  the  neck. 

The  pes  anserinus  (plexus  parotidetis). — The  hreaking  up  of  the  two  terminal 
divisions  of  the  facial  nerve  within  the  substance  of  the  parotid  gland  gives  rise 
to  a  plexus,  the  pes  anserinus  (goose's  foot). 

Bell's  palsy. — 1'aralysis  of  the  facial  nerve  is  known  as  Bell's  palsy,  and  may 
be  either  central  or  peripheral.  A  central  paralysis  is  due  to  involvement  of  the 
nucleus  of  the  nerve,  its  center  in  the  cortex  of  the  brain,  or  the  fibers  connecting 
these,  and  results  from  pressure,  as  by  hemorrhage,  abscess,  or  tumor;  it  may  also 
be  brought  about  by  degenerative  processes  in  the  brain.  A  peripheral  paralvsis 
is  due  to  affection  of  the  trunk  of  the  nerve  within  the  cranial  cavil v  by  tumors 
or  meningitis;  within  the  facial  or  Fallopian  canal,  by  middle  ear  disease  or  frac- 
ture of  the  base  of  the  skull ;  external  to  the  stylo-mastoid  foramen,  by  a  growth 
at  the  stylo-mastoid  foramen,  rapidly  growing  tumors  or  abscess  of  the  parotid 
gland,  division  during  an  operation,  or  exposure  of  the  face  to  cold.  When  the 
lesion  is  situated  beyond  the  origin  of  the  chorda  tympani  nerve  the  muscles 
of  expression  and  the  buccinator  muscle  on  the  same  side  of  the  face  become 
paralysed,  the  mouth  is  drawn  to  the  opposite  side,  and  the  affected  side  of  the 
face  becomes  flattened  and  free  from  wrinkles.  Through  paralysis  of  the  orbicularis 
palpebrarum  muscle  the  eye  on  the  paralyzed  side  remains  open,  and  the  tears  run 
down  the  cheek.  The  anterior  naris  of  the  affected  side  is  smaller  in  appearance 
through  paralysis  of  the  nasal  muscles.  1'aralysi.s  of  the  buccinator  muscle  causes 
the  food  to  collect  between  the  cheek  and  the  teeth  of  the  affected  side.  Through 
paralysis  of  the  orbicularis  oris  muscle  the  saliva  dribbles  from  the  mouth,  and  the 
patient  can  not  whistle.  When  the  lesion  is  situated  in  the  aqueductus  Fallopii 


PLATE  CXL 


t  of  emergenc 
;    of  spinal  accessor 


OPERATION  FOR  EXPOSURE  OF  FACIAL  NERVE. 
536 


PLATE  CXLI. 


Supraorbital  a 
Supraorbital  n. 
Frontal  a. 


Infraorbital  br.of  facial  n. 

oral  br.  of  orbital  n. 
Malar  br.of  facial  n. 

Temporal  br.of  facial  n. 

Temporal  fascia 


Infratrochlea 
n. 

Nasal 
n 


Auriculo-temporal  n. 
Middle  temporal  a. 
.Anterior  auricular  a. 


Superficial  temporal  v 
Superficial  temporal  a. 
'Facial  n. 

Posterior  auricular  a. 
Internal  maxillary  a. 
•Buccal  br.of  facial  .n. 

Inframaxlllary  br.of  facial  n. 


Mental  n!        Mental  a. 


Labial  brt 


Facial  v. 

Facial  a. 

nfraorbital  n. 
Palpebral  br. 
Infraorbital  a. 
Nasal  br. 


Supramaxillary  br.of  facial  n. 
Transverse  facial  a. 


TEMPORAL  FASCIA  AND   NERVES  OF  FACE. 
537 


,-,:;:) 

and  above  the  origin  of  Hie  chorda  tympani  nerve,  there  is  loss  of  the  sense  of 
taste  in  (he  anterior  two-thirds  of  the  tongue  on  the  diseased  side,  and  through 
paralvsis  of  (lie  stapedius  muscle  loud  sounds  are  distressing.  \\'hen  tlie  lesion  is 
eentral  or  in  the  hrain,  the  hrow  and  eyelid  are  not  alfected — /'.  e.,  the  f'rontalis, 
corriigator  supercilii,  and  orhieuhiris  ]>a  Ipehraniin  muscles  are  not  involved.  This 
is  probably  due  to  escape  of  the  fibers  which  arise  from  the  nucleus  of  the  opposite 
side. 

SJHIXIHX,  both  tonic  and  dome,  of  the  muscles  supplied  by  the  facial  nerve 
may  occur.  1'ersi^tent  spasm  oi  these  muscles  is  relieved  by  stretching  the  facial 
nerve. 

Operative  exposure  of  the  facial  nerve. — The  facial  nerve  is  exposed  by 
carrving  a  vertical  incision  from  in  front  of  the  mastoid  process  and  behind  the 
lobule  of  the  ear  downward  toward  the  angle  of  the  lower  jaw,  laying  bare  first 
the  posterior  border  of  the  parotid  gland,  which  is  displaced  forward,  and  then 
the  anterior  border  of  the  sterno-mastoid  muscle  at  its  insertion.  The  parotid 
gland  should  be  separated  from  the  mastoid  process  to  the  depth  of  about  one 
centimeter,  when  the  nerve  may  be  seen.  The  exact  location  of  the  nerve  in  tin- 
wound  can  be  ascertained  by  the  use  of  the  faradic  battery. 

The  trifacial  nerve. — The  branches  of  the  trifacial  or  fifth  nerve  which 
make  their  exit  upon  the  face  are  the  supra-orbital  and  the  supra-trochlcar  (pre- 
viously described),  the  lacrymal,  the  infra-orbital,  the  malar,  the  anterior  branch 
of  the  nasal,  and  the  mental  nerve. 

The  lacrymal  nerve,  the  smallest  of  the  ophthalmic  branches,  supplies  the 
lacrymal  gland,  and  frequently  communicates  with  the  temporal  branch  of  the 
temporo-malar  nerve  in  the  orbit ;  it  sends  a  small  filament — the  palpebral — to 
the  skin  and  conjunctiva  around  the  outer  canthus  of  the  eye. 

The  infra-orbital  nerve,  the  terminal  branch  of  the  superior  maxillary 
division  of  the  trifacial  nerve,  emerges  from  the  infra-orbital  foramen  in  company 
with  the  infra-orbital  artery,  under  cover  of  the  levator  labii  superioris  muscle. 
It  immediately  divides  into  palpebral,  nasal,  and  labial  branches.  The  palpebral 
fn-i/ncJtcs,  the  smallest,  pass  upward  beneath  the  orbicularis  palpebrarum  muscle, 
supply  the  lower  eyelid,  and  communicate  with  the  facial  and  the  malar  branch  of 
the  orbital  or  temporo-malar  nerve.  The  nasal  branches,  three  or  four  in  number, 
pass  inward  under  the  levator  labii  superioris  alseque  nasi  muscle  to  supply  the 
side  of  the  nose,  and  communicate  with  the  external  (naso-labial)  branch  of  the 
nasal  nerve.  The  labial  briuichcx,  usually  four,  are  larger  than  the  palpebral  or 
nasal  branches,  arid  descend  beneath  the  levator  labii  superioris  muscle  to  supply 
the  upper  lip.  Beneath  the  levator  labii  suporioris  the  branches  assist  in  forming 
the  infra-orbital  plexus.  (See  description  of  plexus  under  Facial  Nerve.) 


340  SfRGICAL   ANATOMY. 

Tin;  infra-orbital  artery,  a  branch  uf  ihe  internal  maxillary,  accompanies  the 
infra-orbital  nerve  through  tin-  infra-orbital  foramen,  and  divides  into  l>ranclics 
which  are  distributed  like  tho.se  of  the  nerve.  It  anaMomoses  with  the  1ransvei>e 
facial,  facial,  and  ophthalmic  arteries. 

The  infra-orbital  vein  communicates  with  the  facial  vein  in  front,  and 
empties  into  the  ptcrygoid  plexus  of  veins. 

Th<>  malar  division  of  the  orbital  or  temporo-malar  branch  of  the  >uperior 
maxillary  nerve  makes  its  exit  through  a  foramen  in  the  malar  bone,  pierces  the 
orbicularis  palpebrarum  muscle,  and  supplies  the  skin  of  the  cheek  covering  the 
malar  hone.  It  communicates  with  the  facial  and  the  palpebral  branches  <if  the 
infra-orbital  nerve. 

The  external  or  terminal  branch  of  the  nasal  nerve,  also  known  as  the 
naso-labial,  emerges  between  the  nasal  bone  and  the  lateral  cartilages  of  the  nose, 
supplying  the  tip  of  the  nose  as  it  descends  beneath  the  compressor  narium  muscle. 
It  communicates  with  the  infra-orbital  branches  of  the  facial  and  trifacial  nerve-. 

The  mental  nerve,  the  continuation  of  the  inferior  dental,  emerges  from  the 
mental  foramen  in  company  with  the  mental  artery.  It  divides  beneath  the  de- 
pressor anguli  oris  muscle  into  three  branches,  the  smallest  of  which  descends  to 
supply  the  chin,  while  the  other  two  ascend  to  supply  the  lower  lip.  It  inosculate- 
with  the  supra-maxillary  branch  of  the  facial  nerve. 

The  mental  artery,  the  terminal  portion  of  the  inferior  dental,  supplies  the 
chin  and  anastomoses  with  the  snbmental,  inferior  labial,  and  inferior  coronary 
arteries. 

PTERYGO-MAXILLARY  REGION. 

The  pterygo-maxillary  region  is  the  space  included  between  the  ramus  of  the 
lower  jaw,  externally  ;  the  lateral  wall  of  the  pharynx  and  the  pteiygoid  proce~.- 
of  the  sphenoid  bone,  internally  ;  the  zygomatic  surface  of  the  superior  maxilla, 
anteriorly  ;  and  the  lower  surface  of  the  greater  wing  of  the  sphenoid  and  the 
adjacent  temporal  bone,  above.  The  posterior  limit  of  the  space  is  represented 
by  a  plane  passing  directly  inward  from  the  posterior  border  of  the  ramus  of 
the  inferior  maxilla  to  the  pharynx. 

DISSECTION. — The  zygomatic  arch  should  be  removed  by  sawing  through  the 
zygomatic  processes  of  both  the  malar  and  temporal  bones.  In  the  latter,  the 
point  selected  should  be  just  in  front  of  the  tubercle  of  the  zygoma.  Reflect 
the  masseter  muscle  from  the  ramus  of  the  inferior  maxilla,  carrying  the  zygoma 
with  it ;  locate  the  masseteric  artery  and  nerve  which  pass  through  the  sigmoid 
notch  of  the  lower  jaw  ;  trace  them  into  the  masseter  muscle  as  far  as  possible, 
and  then  sever  them.  A  portion  of  the  ramus  of  the  lower  jaw  should  be 


PLATE  GXLII, 


Anterior  deep  ten 
Superior  maxillary  n. 


Anterior  temporal  n. 
Posterior  temporal  n. 

Posterior  deep  temporal  a. 
,Masseteric  n. 

Temporal  m. 


Orbital  n. 
Infraorbital  a. 


Buccinator  m. 


Auriculo-tempora!  n. 

Superficial  temporal  a. 
Masseteric  a. 
Transverse  facial  a. 
Internal  maxillary  a. 
Inferior  dental  a. 
Posterior  auricular  a. 
Inferior  dental  n. 
External  carotid  a. 


Chorda  tympani  n. 
Internal  lateral  lig. 


Mylo-hyoid  a. 
Mylo-hyoid  n , 
Internal  pterygoid  m. 


Posterior  superior  dental  n! 

Alveolar  a! 
Buccal  a. 

Buccal  nl 
External  pterygoid  m'. 

'ual  n 


Pterygoid  a. 


PTFRYGOIO  MUSCLES  AND  INTERNAL  MAXILLARY  ARTERY. 
542 


PACK.  543 

removed  in  the  following  manner:  With  Hoy's  saw  cut  downward  behind 
the  last  molar  tooth,  half  way  through  the  body  of  the  jaw.  then  backward 
to  near  the  angle.  Discard  the  saw  when  it  readies  the  cancellons  tissue, 
and  use  the  chisel  to  avoid  division  of  the  inferior  dental  vessels  and  nerve. 
The  saw  should  now  be  directed  downward  from  the  sigmoid  notch,  just  in  front 
of  the  neck  of  the  jaw,  through  the  ranius  to  the  end  of  the  incision  in  the  body 
of  the  bone.  The  removal  of  this  portion  of  the  inferior  maxilla  is  tedious,  as  the 
internal  pterygoid  muscle,  internal  lateral  ligament,  and  the  inferior  dental  vessels 
and  nerve  oppose  elevation  of  the  section  of  bone  thus  separated.  Remove  the 
posterior  inferior  corner  of  the  section  of  the  ramus  with  hone  forceps  as  far  as 
the  inferior  dental  canal,  which  contains  the  inferior  dental  vessels  and  nerve; 
then  reflect  the  bone  with  the  lower  portion  of  the  temporal  muscle,  taking  care 
to  avoid  destroying  the  mylo-hyoid  artery  and  nerve  which  arise  from  the  inferior 
dental  artery  and  nerve,  near  the  inferior  dental  foramen,  and  pass  downward  and 
forward  in  a  groove  on  the  internal  surface  of  the  ramus.  In  making  this 
dissection  it  is  advisable  to  use  the  back  of  the  point  of  the  scalpel,  as  the  vessels 
and  nerves  are  small,  of  delicate  structure,  and  are  easily  severed. 

The  contents  of  the  pterygo-maxillary  region  are  the  internal  and  external 
pterygoid  muscles,  the  internal  maxillary  artery  with  some  of  its  branches  and 
their  companion  veins,  the  pterygoid  plexus  of  veins,  the  inferior  maxillary  nerve, 
and  the  following  branches  of  that  nerve:  The  anterior  and  posterior  deep 
temporal,  long  buccal,  masseteric,  internal  and  external  pterygoid,  inferior  dental, 
auricnlo-temporal,  and  lingual  nerves,  the  chorda  tympani  nerve,  a  portion  of  the 
parotid  gland,  the  internal  lateral  ligament  of  the  lower  jaw,  and  the  internal 
maxillary  lymphatic  glands. 

The  internal  maxillary  artery,  which  is  closely  related  to  the  nerves  of  this 
region,  passes  forward  either  over  or  behind  the  external  pterygoid  muscle. 

The  internal  lateral  ligament  is  a  thin,  fibrous  band  which  lies  beneath  the 
inferior  dental  vessels  and  nerve  ;  it  passes,  with  the  lingual  and  inferior  dental 
nerves,  through  the  triangular  interval  between  the  two  pterygoid  muscles  and  the 
incised  edge  of  the  jaw. 

The  external  pterygoid  muscle,  the  more  superficial  of  the  two  pterygoids, 
arises  by  an  upper  head  from  that  portion  of  the  greater  wing  of  the  sphenoid 
bone  situated  between  the  pterygoid  ridge  and  the  foramina  ovale  and  spinosum  ; 
by  a  lower  head  from  the  outer  surface  of  the  external  pterygoid  plate  of  the 
sphenoid  bone,  from  the  tuberosities  of  the  palate  and  superior  maxillary  bones. 
Its  fibers  pass  horizontally  backward  and  converge  for  insertion  into  the  inter- 
articular  fibro-cartilage  of  the  temporo-maxillary  joint  superiorly,  and  inferiorly 
into  the  anterior  portion  of  the  inner  surface  of  the  neck  of  the  inferior  maxilla. 


:>  il  SURGICAL   ANATOMY. 

It  is  related,  externally,  with  the  ramus  of  the  inferior  maxilla,  the  temporal 

and  masseter  muscles,  tin-  superficial  portion  of  the  internal  pterygoid  mu>cle,  the 
internal  maxillary  artery,  the  anterior  and  posterior  deep  temporal  arteries,  and 
the  huccal  artery  and  nerve.  Internally,  it  is  in  relation  with  the  deep  part  of  the 
internal  pterygoid  ninsele,  the  middle  meningeal  artery,  and  the  interior  maxillary 
nerve,  the  internal  lateral  ligament  of  the  lower  jaw,  the  lingual  and  inferior  dental 
nerves,  which  emerge  from  beneath  its  lower  horder  :  the  long  Iniceal  nerve,  which 
runs  between  its  two  heads;  the  chorda  tympani  nerve,  and  the  anterior  and 
posterior  deep  temporal  and  masseteric  nerves,  which  pass  out  from  beneath  the 
upper  border  of  the  muscle. 

Bi.oon  Si  iM'i.Y. — From  the  external  pterygoid  branches  of  the  internal  maxil- 
lary artery. 

NicuvK  SCPPLY. — From  the  inferior  maxillary  nerve. 

ACTION. — The  external  pterygoid  muscles  acting  together  pull  the  lower  jaw 
forward  ;  alternately,  they  move  it  forward  and  laterally  ;  and,  singly,  forward  and 
to  the  opposite  side.  They  are  muscles  of  trituration. 

The  internal  pterygoid  muscle  (the  internal  masseter)  arises  by  two  heads,  a 
superficial  and  a  deep.  The  superficial,  the  smaller,  arises  from  the  lower  and 
back  part  of  the  tubcrosity  of  the  upper  jaw,  and  the  outer  side  of  the  tuberosity  of 
the  palate  bone.  The  deep  lies  behind  the  lower  head  of  the  external  pterygoid 
and  arises  from  the  internal  surface  of  the  external  pterygoid  plate,  and  from  the 
grooved  portion  of  the  tuberosity  of  the  palate  bone  situated  in  the  pterygoid  fossa. 
These  two  heads  unite  at  the  lower  margin  of  the  external  pterygoid  muscle,  and 
thence  extend  downward,  backward,  and  outward  for  insertion  into  the  rough  inner 
surface  of  the  posterior  portion  of  the  ranius  of  the  lower  jaw  included  between 
the  angle  and  the  inferior  dental  foramen. 

It  is  related,  externally,  with  the  ramus  of  the  lower  jaw,  the  external 
pterygoid  muscle,  the  internal  lateral  ligament  of  the  lower  jaw,  the  lingual  or 
gustatory  nerve,  and  inferior  dental  and  mylo-hyoid  vessels  and  nerves ;  internally, 
with  the  tensor  palati,  stylo-glossus,  stylo-hyoid,  posterior  belly  of  the  digastric, 
and  the  superior  constrictor  muscle  of  the  pharynx. 

BLOOD  SUPPLY. — From  the  mylo-hyoid  and  internal  pterygoid  branches  of  the 
internal  maxillary  artery. 

NERVE  SUPPLY. — From  the  internal  pterygoid  branch  of  the  inferior  maxillary 
nerve. 

ACTION. — Both  internal  pterygoid  muscles  acting  together  draw  the  lower  jaw 
upward  and  forward  ;  and,  singly,  upward  and  to  the  opposite  side. 

The  internal  maxillary  artery,  the  larger  of  the  two  terminal  branches  of 
the  external  carotid,  arises  in  the  parotid  gland,  opposite  to  or  slightly  lower  than 


PLATE  CXLIil. 


Infraorbital  a. 


Spheno-palatine  a. 

Pterygo-palatine  a. 
,Vidian  a. 


Orbita!  br. 


Palpebral  br. 

Anterior  dental  br. 
Nasal  br. 
Labial  br. 
Posterior  dental  a 


Gingival  br.of  posterior  dental  a 


Decending  palatine  a. 

Anterior  deep  temporal  a 
External  pterygoid  a. 

Posterior  deep  temporal  a. 
Small  meningeal  a. 
Middle  meningeal  a. 

Superficial  temporal 
a . 

Typanic  a. 
Deep  auricular  a. 
Internal  maxillary  a. 

External  carotid  a 


Masseteric  a. 


Internal  pterygoid  a. 
Inferior  dental  a. 

Buccal  a. 


Mylo  hyoid  a. 
Submental  a. 
Mental  a. 
Incisive  br. 


INTERNAL  MAXILLARY  ARTERY  AND  BRANCHES, 
546 


FACK.  ">;: 

the  neck  of  the  lower  jaw.  The  artery  is  divided  into  three  portions  :  maxillary, 
pterygoid,  and  splieno-ma  x  illary.  Tlie  j!r*t  or  nin.i-il/nri/  jinr/inn  passes  forward 
between  tile  internal  lateral  ligament  and  the  neck  of  the  lower  jaw,  and  reaches 
the  lower  margin  of  the  external  pterygnid  muscle.  The  mm/nl  or  pterygoid  portion 
extends  ohli(|Uely  upward  and  i'orwanl  upon  the  outer  surface  of  the  external 
pterygoid  muscle,  and  is  hidden  hy  the  insertion  of  the  temporal  muscle.  The 
flilril  in-  x/i/i/'iKi-iiKi.ril/iift/  /iiiiii'in  lies  in  the  spheno-maxillary  fossa.  In  some 
instances  the  second  or  pterygoid  portion  runs  entirely  heneath  the  external 
pterygoid  muscle,  hut,  hy  passing  hetween  the  two  heads  of  that  muscle, 
appears  upon  the  outer  surface  of  the  muscle  just  before  entering  the  spheno- 
maxillary  fossa. 

The  In'iini-li «  i if  III'  Jirxf  nr  iii<i.ri/l<ii-i/  IIIII-I'KI/I  i if  tin  i, ili  nuil  in<i.ri!/<irt/  artery 
are:  The  deep  auricular,  tympanic,  middle  meningcal,  small  meningeal,  and 
inferior  dental  arteries. 

The  deep  ai/rii'i//<ir  iir/rri/  pierces  the  wall  of  the  external  auditory  canal  to 
supply  the  tympanic  membrane. 

The  fi/iiijHiiiir  ln-diirli  passes  behind  the  temporo-maxillary  joint  through  the 
Glaserian  fissure  to  supply  the  tympanum. 

The  Hiitlilfr  iiKi/iiii/i'iil  (nlirij  runs  upward  hetween  the  two  roots  of  the 
auricnlo-temporal  nerve  to  the  foramen  spinosuin,  through  which  it  enters  the 
cranial  cavity  to  supply  the  cranium  and  dura  mater. 

The  aiiidll  UK  niiKjiiil  <i  rtcri/  ascends  to  the  foramen  ovale,  through  which,  after 
supplying  a  twig  to  the  nasal  fossa  and  soft  palate,  it  enters  the  cranial  cavity. 

The  inferior  dental  artery,  with  its  vena-  comites,  accompanies  the  inferior 
dental  nerve  and  passes  downward,  upon  the  internal  pterygoid  muscle  and  the 
internal  lateral  ligament,  entering  the  inferior  dental  foramen  together  with  the 
inferior  dental  nerve.  The  artery  then  occupies  the  inferior  dental  canal,  dis- 
tributing branches  to  the  teeth  ;  it  supplies  an  incisive  branch,  and  emerges, 
on  the  face,  from  the  mental  foramen;  it  is  then  called  the  mental  artery;  the 
mental  artery  is  accompanied  by  the  mental  nerve-,  and  is  distributed  to  the 
structures  of  the  chin  and  lower  lip.  Before  entering  the  inferior  dental  canal 
the  inferior  dental  artery  gives  off  the  mylo-liyoid  artcri/,  which  accompanies 
the  mylo-hyoid  nerve. 

The  branches  of  the  second  or  pterygoid  portion  are  the  anterior  and  posterior 
deep  temporal,  internal  and  external  pterygoid,  and  the  masseteric  and  buccal 
arteries. 

The  anterior  and  posterior  <!«•/>  tnii/mmf  urt/rirx  pass  upward  through  the 
corresponding  parts  of  the  temporal  fossa,  between  the  temporal  muscle  and  the 
pericranium,  which  they  supply. 


54S  SURGICAL   ,1  .V.I  To  MY. 

The  /i/i  ri/i/oiil  branches,  varying  in  number,  supply  the  external  and  internal 
pterygoid  muscles. 

The  inii.-ixiti  rii-  /n-ni/rli,  with  the  masseleric  nerve,  passes  outward  behind  the 
temporal  muscle  through  the  sigmoid  notch  of  the  lower  jaw  to  the  massetcr 
muscle. 

Tlie  linrraf  lirnnfli  accompanies  the  long  buccal  nerve  in  its  forward  course 
between  (lie  ramus  of  the  lower  jaw  and  the  external  pterygoid  to  the  buccinator 
muscle. 

The  hra  IK-III  x  i if  tin  /liiril  a,-  xfilii  no-mu.rilliirii  portion  are  the  alveolar,  infra- 
orbital,  posterior  or  descending  palatine,  Yidian,  pterygo-palatine,  and  nas<,- 
palatine  or  spheno-palatine  arteries. 

The  ali'colar  (podrrior  xti/i/ r!nr  <l<ntal  or  poxt<rior  di/iful)  <irt<,'i/  gives  off 
branches  to  the  gums  and  the  buccinator  muscle,  enters  the  superior  maxilla  at 
its  zygomatic  surface,  and  supplies  the  molar  and  bicuspid  teeth  and  the  mucous 
lining  of  the  maxillary  sinus  or  antrum  of  Ilighmore. 

The  infra-orbital  urtcr;/  immediately  enters  the  infra-orbital  groove  and  canal, 
accompanied  by  the  superior  maxillary  division  of  the  fifth  pair  of  cranial  nerves, 
and  eventually  emerges  upon  the  face  in  company  with  the  infra-orbital  nerve  at 
the  infra-orbital  foramen.  It  supplies  branches  to  the  orbit,  and  gives  off  an 
i  interior  superior  di-ntul  ftranrJi,  which  runs  downward  in  the  anterior  wall  of  the 
maxillary  sinus  and  supplies  the  incisor  and  bicuspid  teeth  and  the  mucous 
membrane  of  the  maxillary  sinus. 

The  pnxfrrior  or  ilixrrniJ/ni/  jin/n/inr  iiii/ry  accompanies  the  posterior  palatine 
branches  of  Meckel's  or  the  spheno-palatine  ganglion  of  the  fifth  pair  of  cranial 
nerves,  through  the  posterior  palatine  canal,  then  emerges  from  the  posterior 
palatine  foramen,  and  passes  forward  in  a  groove  situated  near  the  alveolar  process 
along  the  under  surface  of  the  hard  palate  ;  it  next  enters  the  foramen  of  Stenson, 
a  subdivision  of  the  anterior  palatine  foramen,  and  anastomoses  with  the  n  a  so- 
palatine  artery.  It  is  distributed  to  the  hard  and  soft  palate,  palatine  glands,  and 
gums. 

The  Vidian  branch  runs  backward  with  the  Yidian  nerve  through  the  Yidian 
canal  to  supply  the  uppermost  part  of  the  pharynx,  the  Eustachian  tube,  and  the 
tympanum. 

The  pterygo-palatvne  branch,  which  is  very  small,  passes  backward  with  the 
pharyngeal  nerve  through  the  pterygo-palatine  canal  to  supply  the  upper  pharynx, 
the  sphenoid  cells,  and  the  Eustachian  tube. 

The  naso-palatine  or  spheno-palatine,  the  terminal  branch,  runs  inward  through 
the  naso-palatine  or  spheno-palatine  foramen  into  the  superior  meatus  of  the  nose. 
It  crosses  the  roof  of  this  meatus  between  the  mucous  membrane  and  the  bone  to 


PLATE  CXLIV, 


Anterior  deep  temporal  a 
Anterior  temporal  n, 

Orbital  n 

Superior  maxillary  n. 
Meckel's   ganglion. 
Infraorbital  a.- 


Posterior  superior  dental  n. 
Posterior  temporal  n. 
Inferior  maxillary  n 

Long  buccal  n 
Chorda  tympani  n 

Lingual  n 

Internal  lateral  ligament 

of  lower  jaw 

Buccinator  m. 
inferior  dental  n. 

Inferior  dental  a, 


Superficial  temporal  a. 
Auriculo-temr 


Middle  meningeat  a. 
Tympanic  a. 

Small  meningeal  a, 
nternal  maxillary  a. 
External  carotid  a. 
nferior  dental  a. 
nternal  pterygoid  m. 


Myio-hyoid  a. 
Mylo-hyoid  n. 


INFERIOR  MAXILLARY  NERVE. 
550 


FA<-E.  .".",  l 

reach  the  septum  uf  tli-  nose,  run-  downward  and  forward  in  a  groove  on  the 
VOIIHT,  to  anastomose  witli  the  posterior  palatine  artery.  Two  or  three  external 
branehes  are  distributed  to  the  mucous  lining  of  the  lateral  nasal  walls,  the  antruin 
of  Ilighmore  and  the  ethmoid  and  sphenoid  cells. 

The  veins  of  the  pterygo-maxillary  region  accompany  the  branches  of  the 
internal  maxillary  artery,  and  converge  toward  the  external  pterygoid  muscle, 
around  which  they  form  a  dense  plexus — the  pterygoid  plexus.  This  is  drained 
from  its  posterior  part  by  a  short  venous  trunk,  called  the  wnjternal  iiin.riflfiri/  vein, 
which  accompanies  the  first  (maxillary)  portion  of  the  internal  maxillary  artery 
into  the  substance  of  the  parotid  inland.  The  internal  maxillary  vein  joins  the 
temporal  vein  to  form  the  temporo-maxillary  vein.  The  pterygoid  plexus  sends 
a  branch  (unti  ri»r  iiiii.ri/lin'i/  or  d-cp  facial  vein)  from  its  anterior  part  over  the 
buccinator  muscle  to  the  facial  vein.  It  also  communicates  with  the  cavernous 
sinus  by  means  of  a  small  emissary  vein  which  passes  through  the  foramen 
Yesalii  in  the  sphenoid  bone. 

The  lymphatics  of  this  region  accompany  the  blood-vessels,  and  are  derived 
from  the  regions  which  those  vessels  supply  and  drain.  They  empty  into  the  deep 
cervical  glands. 

The  nerves  of  the  pterygo-maxillary  region  are  the  inferior  maxillary  division 

of  the  fifth  nerve  and  some  of  its  branches  and  the  chorda   tympani  nerve. 

The  inferior  iiiii.r!llin-i/  ncrrr  leaves  the  cranial  cavity  through  the  foramen  ovale. 
It  emerges  from  the  skull  as  a  thick  trunk,  which  lies  external  to  the  Kustachian 
tube  and  beneath  the  external  pterygoid  muscle.  It  dill'ers  from  the  other  two 
divisions  of  the  fifth  nerve — the  ophthalmic  and  the  superior  maxillary — in  being 
composed  of  both  motor  and  sensory  fibers.  After  leaving  the  skull  it  divides  into 
two  portions.au  anterior  and  a  posterior.  From  the  nnf>  rinr  jim-timi,  chiefly  motor, 
are  derived  the  anterior  and  posterior  deep  temporal  nerves,  the  masseteric  nerve, 
branches  to  the  pterygoid  muscles,  and  the  long  buccal  nerve.  The  pnxftrior  i/iri- 
*io,i,  chiefly  sensory,  divides  into  three  large  branches:  the  aurieulo-temporal,  the 
lingual  (gustatory),  and  the  inferior  dental  nerve. 

The  deep  temporal  nerves,  anterior  and  posterior,  arise  from  the  motor  root 
of  the  fifth  nerve,  and  ascend  between  the  pericranium  and  the  temporal  muscle, 
which  muscle  they  supply. 

The  masseteric  nerve  emerges  from  between  the  external  pterygoid  muscle 
and  the  pterygoid  ridge.  It  proceeds  backward  along  the  upper  border. of  the 
external  pterygoid  muscle  :  outward  in  front  of  the  temporo-maxillary  articulation, 
and  through  the  sigmoid  notch  of  the  lower  jaw,  together  with  the  masseteric  artery, 
entering  the  masseter  muscle,  which  it  supplies. 

The  branch  to  the  internal  pterygoid  muscle  arises  from  the  inferior  maxil- 


">-2  SURGICAL   ANATOMY. 

lary  nerve  before  it  divides  :  il  gives  off  a  branch  to  tlic  otic  ganglion,  and  enti -r- 
the  dcr|i  Mirface  of  the  muscle.  The  branch  to  the  external  pterygoid  muscle  is. 
usually,  a  twig  of  tin'  long  buccal  nerve,  ami  divides  into  two  branches,  which 
enter  the  deep  -nirface  of  tin-  muscle. 

The  long  buccal,  a  sensory  nerve,  is  derived  from  the  anterior  portion  of  the 
inferior  maxillary  division  of  the  fifth  nerve.  It  runs  between  the  two  heads  of 
the  external  pterygoid  muscle,  and  passes  downward  and  forward  beneath  the 
temporal  muscle  and  the  anterior  edge  of  the  masseter  to  the  buccinator  muscle. 
upon  the  outer  side  of  which  it  communicates  with  the  facial  nerve  and  forms  a 
plexus  from  which  filaments  pass  to  the  adjacent  mucous  membrane  and  skin  of 
the  cheek.  It  contains  all  of  the  sensory  libers  of  the  anterior  division  of  the 
inferior  maxillary  nerve,  and  a  few  fibers  from  the  motor  root  of  the  lifth  nerve. 
The  motor  fibers  run  to  the  external  pterygoid  and  temporal  muscles. 

The  auriculo-temporal  nerve  arises  by  two  roots,  between  which  passes  the 
middle  meningeal  artery.  It  runs  backward  and  outward  beneath  the  external 
pterygoid  muscle,  bet  ween  the  internal  lateral  ligament  and  the  temporo-maxillary 
joint,  curves  outward  around  the.  neck  of  the  condvle  of  the  lower  jaw,  and  pierces 
the  upper  part  of  the  parotid  gland.  It  next  ascends  over  the  root  of  the  zygoma, 
in  front  of  the  external  auditory  meatus  and  beneath  the  temporal  artery.  In  its 
course  it  receives  communicating  twigs  from  the  otic  ganglion,  and  supplies 
branches  to  the  external  auditory  meatus,  the  parotid  gland,  and  the  temporo- 
maxillary  articulation.  From  the  parotid  gland  it  sends  a  communicating  branch 
to  the  temporo-faeial  division  of  the  facial  nerve.  It  divides  near  the  level  of  the 
tragus  into  the  anterior  auricular  and  superficial  temporal  branches.  The  unt<  rinr 
auricular  supplies  the  upper  part  of  the  pinna.  The  SHJH  rliritil  fim/>»r<i/  lies  on 
the  outer  side  of  the  superficial  temporal  vessels,  divides,  and  accompanies  the 
anterior  and  posterior  temporal  arteries. 

The  lingual  (gustatory)  nerve  emerges  from  beneath  the  lower  edge  of  the 
external  pterygoid  muscle,  whence  it  descends  internal  to  the  inferior  dental  nerve 
between  the  lower  jaw  and  the  internal  pterygoid  muscle;  thence  it  runs  beneath 
the  mylo-hyoid  nerve  and  over  the  superior  constrictor  of  the  pharynx,  the  stylo- 
glossus,  hyo-glossus,  Wharton's  duct,  and  genio-hyo-glossus  muscle,  to  the  tip  of 
the  tongue.  On  the  hyo-glossus  muscle  it  is  connected  with  the  submaxillary 
ganglion,  which  will  be  described  with  the  submaxillary  triangle  of  the  neck.  It 
lies  above  the  ganglion  and  Wharton's  duct,  which  il  crosses  at  the  anterior  border 
of  the  hyo-glossus  muscle,  where  it  supplies  a  branch  to  the  snblingual  gland  and 
a  communicating  branch  to  the  hypo-glossal  nerve.  Before  it  emerges  from  behind 
the  external  pterygoid  muscle  it  is  joined  by  the  chorda  tympani  nerve. 

The  lingual  nerve  supplies  branches  to  the  hypo-glossal  nerve,  submaxillary 


PLATE  CXLV. 


Nasal  n. 


Olfactory  n. 

Olfactory  tract 


Superior  nasal  nerves 
Spheno-palatine  n. 


Meckel's  ganglion 
Vidian  n. 
,  Pharyngea!  n. 

Naso-palatine  n. 


Naso-palatine  n. 


Inferior  nasal  nerves 

Great  palatine  n 
External  palatine  n. 

Posterior  palatine  n! 

Tensor  palati  m'. 
Internal  pterygoid  m 

Otic  ganglion 
Smpathetic  root  of  otic  gang! 

Middle  meningeal  a. 
Auriculo-temporal  n 


OLFACTORY  NERVES  AND   INTERNAL  VIEW  OF  THE  SPHENO-PALATINE  AND  OTIC  GANGLIA, 

554 


FACE. 

ganglion,  mucous  membrane  of  the  mouth,  gums,  subliugual  gland,  and  lingual 
branches  to  tin1  papilla'  on  tin-  sides  and  tip  of  the  tongue.  As  the  lingual 
nerve  supplies  the  tongue  with  common  sensation,  the  pain  due  to  neuralgia  or 
cancer  of  ihe  tongue  may  ]»•  relieved  l>y  division  of  this  nerve.  The  incision 
should  he  made  through  the  nineous  membrane  of  the  floor  of  the  mouth  opposite 
the  second  molar  tooth  of  the  lower  jaw  and  close  to  the  gum,  where  the  nerve  lies 
immediately  beneath  the  mucous  membrane. 

The  inferior  dental  nerve,  the  largest  branch  of  the  inferior  maxillary. 
emerges  from  beneath  the  lower  head  of  the  external  pterygoid  muscle  and  de- 
scends between  the  internal  lateral  ligament  and  the  ram  us  of  the.  lower  jaw  to 
enter  the  inferior  dental  canal.  At  its  origin  it  lies  internal  to  the  inferior  dental 
artery,  which  it  crosses  at  the  inferior  dental  foramen  ;  the  artery  is,  therefore, 
nearer  the  teeth  than  the  nerve.  It  is  a  sensory  motor  nerve,  lying  external  to  the 
lingual  nerve  and  more  superficial,  the  motor  filaments  bein.ii  given  off  as  the 
mylo-hyoid  nerve  just  previous  to  its  entrance  into  the  inferior  dental  canal. 

The  mylo-hyoid  nerve  is  accompanied  by  the  mylo-liyoid  arterv,  pierces  the 
internal  lateral  ligament  of  the  lower  jaw,  and  descends  to  the  mylo-hyoid  groove 
upon  the  inner  surface  of  the  lower  jaw.  It  then  runs  over  the  superficial  surface 
of  the  mylo-hyoid  muscle,  supplying  it  and  the  anterior  belly  of  the  digastric 
muscle.  In  the  interior  dental  canal  the  inferior  dental  nerve  supplies  branches  to 
the  molar  and  bicuspid  teeth  and  to  the  gums,  and  divides  into  an  incisive  and  a 
mental  branch  opposite  the  mental  foramen. 

The  incisive  branch  passes  forward  and  inward  in  the  inferior  dental  canal 
to  supply  the  canine  and  incisor  teeth  and  the  adjacent  region  of  the  gum. 

The  mental  branch  emerges  upon  the  face  at  the  mental  foramen,  and  after 
communicating  with  the  supra-maxillary  branch  of  the  facial  nerve  divides  into 
several  branches.  These  supply  the  mucous  membrane  of  the  lower  lip  and  the 
fascia  and  skin  of  the  lip  and  chin. 

The  chorda  tympani  nerve  arises  from  the  facial  in  the  aqueductus  Fallopii, 
almost  one-fourth  of  an  inch  above  the  stylo-mastoid  foramen.  It  runs  in  the 
iter  chordae  posterius  to  the  middle  ear,  where  it  passes  between  the  handle  of  the 
malleus  and  the  fibrous  layer  of  the  membrana  tympani  externally,  and  the 
mucous  membrane  internally.  It  next  enters  the  iter  chordse  anterius,  or  canal 
of  Huguier,  to  reach  the  pterygo-maxillary  region,  where  it  joins  the  outer  side 
of  the  lingual  nerve  beneath  the  external  pterygoid  muscle.  Some  of  its 
fibers  leave  the  lingual  nerve  to  enter  the  subjnaxillary  ganglion  and  sublingual 
gland. 

The  otic  (Arnold's)  ganglion  lies  upon  the  internal  surface  of  the  trunk 
of  the  inferior  maxillary  division  of  the  fifth  nerve,  in  front  of  the  middle 


556  SURGICAL   ANATOMY. 

meningeal  artery,  and  may  be  found  by  tracing  any  of  tin-  larger  branches  of 
the  nerve  until  the  root  of  the  parent  stem,  near  the  foramen  uvale.  is  reaelieil. 
tts  sympathetic  rool  is  derived  from  the  plexus  on  the  middle  meningeal  artery; 
its  sensory  rum  from  the  inferior  maxillary  through  the  internal  pterygoid  nerve; 
its  motor  root  from  the  small  superficial  petrosul  nerve,  which  communicates 
with  the  tympanic  branch  of  the  glosso-pharyngeal  nerve.  It  communicates 
with  the  auricmo-temporal  and  chorda  tympani  nerves.  Motor  libers  of  the 
inferior  maxillary  nerve  pass  through  it  to  the  tensor  palati  and  tensor  tympani 
muscles. 

DISSECTION. — To  study  the  first  portion  of  the  internal  maxillary  artery  and 
its  branches,  the  trunk  of  the  inferior  maxillary  nerve,  the  origins  of  its  branches, 
and  the-  otic  ganglion,  it  is  necessary  to  remove  the  external  pterygoid  muscle, 
the  condyle  of  the  jaw,  and  the  remainder  of  the  ramus  as  far  as  the  transverse 
incision  in  the  ramus. 

Fracture  of  the  base  of  the  skull  may  cause  serious  hemorrhage  into  the 
pterygo-maxillary  region,  because  of  rupture  of  the  meiiingcal  vessels.  Lacerations 
of  the  deep  temporal  vessels  due  to  cranial  fracture  would  result  in  the  elfusion  of 
blood  into  this  space,  its  escape  above  the  zygoma  being  rendered  impossible 
because  of  the  attachments  of  the  temporal  fascia.  Under  these  conditions  pain  on 
pressure  made  below  the  zygoma  and  behind  the  malar  bone  would  be  a  rational 
symptom.  Such  effusion  might  give  rise  to  secondary  irritation  of  the  nerves 
in  this  space.  Thus,  irritation  of  the  chorda  tympani  nerve  would  cause  sali- 
vation ;  of  the  lingual,  disturbances  of  sensation  and  laste  at  the  end  of  the 
tongue;  of  the  inferior  dental,  toothache;  of  the  motor  branches,  tonic  or  clonic 
spasms  of  the  muscles  of  mastication  ;  of  the  mylo-hyoid  and  anterior  belly  of  the 
digastric  muscles,  more  or  less  complete  fixation  of  the  jaw. 

Tumors  and  abscess  would  have  similar  effects,  but  would  vary  in  degree  in 
accordance  with  the  exact  location  and  rapidity  of  growth.  Owing  to  the  presence 
of  important  structures  in  this  space,  it  is  well  to  practise  Hilton's  method  of 
opening  a  deep  abscess  in  this  region;  this  is  done  as  follows:  Through  an 
incision  in  the  skin  push  a  grooved  director  into  the  abscess;  then  insert  a  pair 
of  forceps  along  the  director,  and  withdraw  them  with  the  blades  sufficiently 
separated  to  make  an  opening  large  enough  to  insure  good  drainage.  It  is  im- 
possible to  do  serious  damage  by  this  procedure. 

DISSECTION. — The  pterygo-maxillary  region  should  now  be  thoroughly 
cleaned,  in  order  to  study  the  spheno-maxillary  fissure,  the  pterygo-maxillary 
fissure,  and  the  spheno-maxillary  fossa. 

It  will  be  remembered  that  the  zygomatic  fossa  was  mentioned  in  connection 
with  the  contents  of  the  pterygo-maxillary  region  ;  its  contents  have  been  dissected. 


FA  CE.  557 

They  consist  of  the  lower  part  of  the  temporal  muscle,  the  internal  and  external 
pterygoid  muscles,  the  internal  maxillary  artery,  the  inferior  maxillary  nerve, 
hranehes  of  the  artery  and  nerve,  and  the  chorda  tympani  nerve. 

The  zygomatic  fossa  practically  corresponds  to  the  upper  portion  of  the 
pterygo-maxillary  region.  It  is  hounded  ahove  l>y  the  under  surface  of  the  great 
wing  of  the  sphenoid  and  adjacent  portion  of  the  temporal  bone:  in  front,  by  the 
7,ygomatic  surface  of  the  superior  maxilla  ;  behind,  by  the  posterior  border  of  the 
pterygoid  process  of  the  sphenoid  bone  and  the  eminentia  articularis  ;  internally, 
bv  the  external  ptcrygoid  plate:  and  externally,  by  the  pterygoid  ridge,  the  xvgo- 
matie  arch,  and  the  ranius  of  the  inferior  maxilla.  At  the  upper  and  inner  part  of 
the  zygomatic  fossa  two  fissures  will  be  observed,  one  horizontal,  the  other  vertical. 
The  horizontal  fissure  is  the  spheno-maxillary,  which  opens  into  the  outer  and  back 
part  of  the  orbit.  It  transmits  the  infra-orbital  artery  and  vein,  branches  from 
Meckel's  ganglion,  and  the  superior  maxillary  nerve  and  its  orbital  branch.  Its 
bony  walls  are  formed,  above,  by  the  lower  border  of  the  orbital  surface  of  the  great 
wing  of  the  sphenoid  ;  below,  by  the  orbital  surface  of  the  superior  maxilla  and  a 
portion  of  the  palate  bone  ;  externally,  by  a  small  part  of  the  malar  bone.  It  joins 
the  pterygo-maxillary  fissure  at  a  right  angle.  The  vertical  fissure  is  the  pterygo- 
maxillary,  which  is  formed  by  the  angle  between  the  superior  maxillary  bone  and 
the  pterygoid  process  of  the  sphenoid  bone.  It  transmits  the  internal  maxillary 
artery. 

The  spheno-maxillary  fossa  lies  below  the  great  wing  of  the  sphenoid, 
external  to  the  vertical  portion  of  the  palate  bone,  and  between  the  orbital  process 
of  the  palate  bone  and  the  zygomatic  surface  of  the  superior  maxilla,  in  front,  and 
the  pterygoid  process,  behind.  It  contains  the  terminal  portion  of  the  internal 
maxillary  artery,  the  branches  of  this  portion,  the  superior  maxillary  nerve,  and 
Meckel's  ganglion.  Three  foramina  are  found  in  the  posterior  wall :  the  fonnmn 
rotundum,  which  transmits  the  superior  maxillary  division  of  the  fifth  nerve  ;  below 
this,  the  anterior  opening  of  the  Vidian  canal,  which  transmits  the  Yidian  nerve 
and  vessels,  and  still  lower  the  ptcrt/yo-palatine  foramen — the  anterior  opening  of 
the  pterygo-palatine  canal,  which  transmits  the  pterygo-palatine  vessels  and  the 
pharyngeal  nerve.  On  the  internal  wall  is  the  splifmi-jiiihitini-  foramen,  which 
transmits  the  spheno-palatine  vessels  and  the  naso-palatine  nerve.  Below  the 
spheno-palatine  foramen  is  the  orifice  of  the  posterior  palatine  canal,  which  trans- 
mits the  posterior  or  descending  palatine  vessels  and  nerve. 

The  superior  maxillary  (second  division  of  the  fifth)  nerve  is  a  sensory 
nerve.  It  arises  from  the  Gasserian  ganglion  at  the  apex  of  the  petrous  portion 
of  the  temporal  bone,  passes  through  the  foramen  rotundum  into  the  spheno- 
maxillary  fossa,  and  enters  the  infra-orbital  canal  with  the  infra-orbital  artery  to 


558  SURGICAL   .I.V.I  T<> MY. 

become  the.  infra-orbital  nerve.  Its  branches  arc:  In  the  cranial  cavity,  recurrent 
twiyx  to  tlie  dura  mater,  which  communicate  with  liranchcs  of  the  inferior  maxillary 
nerve;  in  the  spheno-maxillary  fossa,  orbital  or  temporo-malar,  spheno-palatine,  and 
jinx/i  r!ur  xiijn  rinr  <li  iiful  /n-ni/r/nx ;  in  the  infra-orbital  canal,  middle  superior  dental 
and  iiufi  /•/</;•  xiijH-rinr  i/riifiil  nerves;  and  upon  the  face,  the  terminal  divisions  of  the 
infra-orhital  nerve,  the  jinl/n  tirnl.  nnxal.  and  la/, in/  /irmic/ics.  In  the  spheno- 
maxillary  fossa  Meckel's  ganglion  is  associated  witli  it. 

DISSKC  TIOX. — Remove  the  outer  wall  of  the  orhit  and  that  portion  of  the 
greater  wing  of  the  sphenoid  bone  external  to  the  foramen  rotnndum  by  sawing 
downward  from  the  incised  edge  of  the  skull  made  in  removing  the  brain.  The 
saw  should  pass  through  the  outer  part  of  the  sphenoid  fissure  and  external  to  the 
foramen  rotnndum. 

The  orbital  or  temporo-malar  nerve  enters  the  orbit  through  the  spheim- 
maxillary  fissure.  At  the  posterior  part  of  the  orbit  it  divides  into  a  temporal 
and  a  malar  branch.  The  fnn/mra/  Imnich  runs  forward  in  the  periosteum,  lying 
in  a  groove  in  the  hone,  and  passes  through  a  foramen  in  the  malar  bone  (spheno- 
malar  foramen)  to  enter  the  temporal  fossa.  It  runs  upward  beneath  the  temporal 
muscle,  piercing  it  and  both  lamella}  of  the  temporal  fascia  to  supply  the  skin  of 
the  temporal  region;  it  pierces  the  superficial  layer  of  the  temporal  fascia  about 
an  inch  above  the  y.ygoma.  In  the  orbit  it  communicates  with  the  lacrymal 
nerve;  and  in  the  temporal  region  with  the  temporal  branch  of  the  facial  nerve. 
The  malar  I/ranch  (ramns  snbcutaneus  mala?)  runs  forward  along  the  external  and 
inferior  portion  of  the  orbit,  passes  through  the  malar  foramen,  pierces  the  orbicu- 
laris  palpebrarum,  and  supplies  the  skin  of  the  cheek.  It  communicates  with 
the  malar  branch  of  the  facial  nerve  and  with  the  palpebral  branches  of  the  infra- 
orbital  nerve. 

The  spheno-palatine  branches  are  two  twigs  which  descend  to  Meckel's 
ganglion  from  its  sensory  root. 

The  posterior  superior  dental  nerves  are,  usually,  two  in  number,  and  arise 
from  the  superior  maxillary  nerve  as  it  enters  the  infra-orbital  canal.  They  pass 
downward  and  enter  the  foramina  in  the  zygomatic  surface  of  the  superior  maxilla  ; 
they  next  run  forward  in  canals  in  the  outer  wall  of  the  ant  rum  of  High  in  ore 
and  above  the  roots  of  the  molar  teeth  to  join  the  middle  superior  dental  nerve. 
They  supply  branches  to  the  pulp  of  the  molar  teeth,  to  the  gums,  and  to  the  mucous 
membrane  of  the  an  tram  of  Highmore. 

The  middle  superior  dental  nerve  is  given  off  at  the  posterior  part  of  the 
infra-orbital  canal,  or  it  may  be  a  branch  of  the  anterior  superior  dental  nerve.  It 
supplies  the  bicuspid  teeth  and  communicates  with  the  anterior  superior  and 
posterior  superior  dental  nerves. 


PLATE  CXLVI. 


Infraorbital   a. 

Infraorbital  n. 

Posterior  superior  dental  n, 
Orbital  n. 

Spheno-palatine  n. 
Vidlan  n. 


Middle  superior  dental  a 
Middle  superior  dental  n.. 
Anterior  superior  dental  a.. 
Anterior  superior  dental  n. 
Palpebral  branch 


Internal  maxillary  a. 

Ophthalmic  div.  of  5th  n. 
Superior  maxillary  n. 

Inferior  maxillary  n. 
Gasserian  ganglion 


Nasal  branches 
Labial  branch 


Gingival  a.- 


Aunculo-temporal  n. 


Middle  meningeai 
Small  meningeai  a. 
Inferior  dental  a. 
Inferior  dental  n. 


Incisive  br. 


Mylo-hyoid  n. 
Chorda  tympani  rl. 
Lingual  n. 


SUPERIOR  AND  INFERIOR  MAXILLARY  NERVES. 
559 


FACE.  ">G1 

anterior  superior  dental  nerve  is  larger  than  the  other  two  superior 
dental  uerves,  and  arises  posterior  to  the  infra-orbital  t'oraineii  ;  it  runs  downward 
in  the  anterior  wall  of  the  untrum  of  1 1  ighmoiv.  and  supplies  the  im-i<oi-  and 
canine  teeth,  and  also  a  branch  to  the  nasal  fossa.  The  anterior  and  middle 
superior  dental  nerves  may  he  seen  by  raising  the  superior  maxillary  nerve  from 
the  Hour  of  the  infra-orbital  canal. 

The  infra-orbital  nenre  emerges  upon  the  face  at  the  infra-orbital  foramen, 
whieh  lies  heneath  the  levator  lahii  superioris  muscle.  It  divides  here  into  palpe- 
hral.  nasal,  and  lahial  branches,  which,  with  the  infra-orbital  branch  of  the  facial 
nerve,  form  the  infra-orbital  plexus. 

The  pu/jit />,•<!/  In-inn-lits  ]iierce  the  origin  of  the  levator  lahii  superioris  muscle 
and  supply  the  internment  and  conjunetiva  of  the  lower  eyelid. 

The  'iiiixiil  In-iiiii-lii'x  pass  inward  under  the  levator  lahii  superioris  alaM|ue  nasi 
muscle  to  supply  the  skin  of  the  nose. 

The  Inliinl  /n-iiiK-li/.-i  are  the  largest  and  most  numerous.  They  run  downward 
heneath  the  levator  labii  superioris  muscle  to  supply  the  skin,  mucous  membrane, 
and  other  tissues  of  the  upper  lip. 

Meckel's  or  the  spheno-palatine  ganglion  is  situated  in  the spheno-maxillary 
fossa  below  the  superior  maxillary  nerve.  It  is  triangular  in  shape,  of  a  reddish- 
gray  color,  and  measures  about  one-tilth  of  an  inch  in  its  longest  diameter.  Its 
sensory  root  is  derived  from  the  superior  maxillary  through  the  spheno-palatine 
nerve,  most  of  the  fibers  of  which  do  not  enter  the  ganglion  hut  pass  anterior  to  it. 
Its  motor  rout  is  derived  from  the  facial  through  the  great  superficial  petrosal 
nerve,  which  assists  the  great  deep  petrosal  in  forming  the  Viclian  nerve.  Its 
sympathetic  root,  the  great  deep  petrosal  nerve,  just  mentioned,  is  derived  from  the 
carotid  plexus.  The  motor  and  sympathetic  roots  enter  the  spheno-maxillary 
fu—a  as  the  Yidian  nerve.  Its  branches  are  classified  as  ascending,  descending, 
internal,  and  posterior. 

The  ascending  or  orbital  branches  pass  through  the  spheno-maxillary  fissure, 
and  pierce  the  inner  wall  of  the  orbit  to  supply  the  mucous  membrane  of  the 
sphenoid  sinus  and  posterior  ethmoid  cells. 

The  descending  or  palatine  branches  are  derived  mainly  from  the  spheno- 
palatine  brandies  of  the  superior  maxillary  nerve.  They  are  divided  into  anterior, 
external,  and  posterior  palatine  nerves.  ' 

The  null  i-ifn-  i>r  lurt/r  /ni/<i/iiir  in-riT  passes  down  ward  in  the  posterior  palatine 
canal  together  with  the  posterior  palatine  artery,  and  appears  on  the  hard  palate  at 
the  posterior  palatine  foramen.  It  runs  forward  in  a  groove  on  the  under  surface  of 
the  hard  palate,  and  joins  the  terminal  portion  of  the  naso-palatine  nerve.  It  sup- 
plies the  gums  and  the  miieo-periosteum  of  the  hard  palate.  While  in  the  poste- 
36 


SURGICAL    ANATOMY. 

rior  palatine  canal  it  gives  <>H'  two  branches  (inferior  nasal  nerve-),  which  pierce 
tin-  vortical  plate  of  the  palate  bone  tn  supply  the  mumus  membrane  of  the  hack 
part  ui'  the  middle  and  inlerinr  ineatuses  ami  the  inferior  turhinated  hone. 

The  external  or  niit/<l/<  /><i/<itini'  nerve,  when  present,  is  small  ;  it  descends  in 
the  external  palatine  canal  to  supply  the  tonsil  and  adjacent  mucous  ineiiihrane. 

The  posterior  or  small  palatine  nerw  descends  in  the  accessory  palatine  canal 
to  supply  the  tonsil,  adjacent  mucous  nieinhrane,  levator  palati,  and  a/ygos  uvuhe 
muscles.  With  the  external  palatine  nerve  it  joins  a  hranch  from  the  glosso- 
pharyngeal  nerve  to  form  the  i-'nrnlux  tonxi/lnrix.  a  plexus  around  the  tonsil. 

The  internal  or  nasal  branches  are  derived  partly  from  the  sphenopalatine 
ganglion  and  partly  from  the  Bpheno-palatine  nerve.  They  are  divided  into  sejital 
and  superior  nasal  brandies. 

The  x< jitnl  ln-iiitdiix  pass  through  the  spheno-palatine  foramen  with  the  naso- 
palatine  artery,  and  cross  the  roof  of  the  nasal  fossa  beneath  the  mucous  mem- 
brane and  below  the  opening  of  the  sphenoid  sinus  to  reach  the  septum,  where  the 
smaller  branches  terminate. 

The  iinxn-/>ii!'it!iif  nerve  (nerve  of  Cotunnius),  the  largest  of  these  brandies, 
runs  downward  and  forward  on  the  septum  of  the  nose,  between  the  periosteum 
and  the  mucous  membrane,  to  the  anterior  palatine  canal,  where  it  passes  through 
one  of  the  foramina  of  Scarpa  (subdivisions  of  the  anterior  palatine  foramen)  to 
supply  the  mucous  membrane  of  the  anterior  portion  of  the  hard  palate  and  to 
join  the  terminal  portion  of  the  anterior  palatine  nerve. 

The  superior  /mxnl  nerves  are  several  twigs  which  pass  through  the  spheno- 
palatine foramen  to  supply  the  mucous  membrane  of  the  posterior  part  of  the 
middle  and  superior  turbinated  bones,  and  of  the  posterior  ethmoid  cells  and 
antrum  of  Highmore. 

The  posterior  branch  is  the  pharyngeal  nerve. 

The  pharyngeal  or  pterygo-palatine  nerve  runs  backward  through  the 
pterygo-palatine  canal  in  company  with  the  pterygo-palatine  artery;  it  supplies 
the  upper  portion  of  the  pharynx  and  the  Eustachian  tube. 

The  Vidian  nerve  has  been  considered  a  posterior  branch  of  the  spheno- 
palatine ganglion,  but  it  is  really  the  nerve  which  is  formed  by  the  junction  of  its 
motor  and  sympathetic  roots.  It  will  be  seen  emerging  from  the  Yidian  canal  at 
the  root  of  the  pterygoid  process. 

The  superior  maxillary  nerve  and  its  many  communications  are  especially 
important,  because  it  is  so  frequently  affected  by  neuralgia,  the  operation  for 
which  follows. 

Trifacial  neuralgia  may  be  due  to  many  causes  ;  among  these  are  :  Reflected 
irritation  from  diseased  teeth,  eruption  of  the  wisdom  teeth,  irritable  ulcers  in  the 


FACE. 

area  of  distribution  of  the  nerve,  ami  abscess  or  tumors  of  the  antruni  of  Iliglnnore, 
of  the  ptcrygo-niaxillary  region,  or  of  the  spheno-maxillary  fossa.  Tlie  infra-orbital 
foramen  is  on  a  line  drawn  from  the  supra-orbital  notch  to  a  point  between  the 
bicuspid  teeth  of  the  upper  jaw.  It  corresponds  to  a  point  ahont  one-half  of  an 
inch  below  the  junction  of  the  inner  and  the  middle  one-third  of  the  infra-orbital 
margin.  The  infra-orbital  nerve  is  best  exposed  through  a  semilnnar  incision  with 
iN  convexitv  directed  downward,  and  carried  a  short  distance  below  the  foramen. 
A  Hap,  including  skin,  cellular  tissue,  and  the  orbicnlaris  palpebrarum  muscle,  is 
raised.  The  levator  labii  superioris  muscle,  which  covers  the  foramen,  is  now 
apparent,  and  mu>t  he  displaced  laterally  or  divided,  when  both  the  infra-oijiital 
plexus  and  nerve  will  readily  be  found,  surrounded  by  a  small  quantity  of  fatty 
tissue. 

In  some  cases  of  obstinate  neuralgia  of  the  peripheral  branches  of  the  trifacial 
nerve  it  becomes  necessary  to  remove  a  portion  of  the  affected  nerve  in  order 
to  give  the  patient  relief.  The  infra-orbital  nerve  may  be  divided  at  its  exit  from 
the  infra-orbital  foramen  by  either  a  subcutaneous  or  a  conjunctiva!  section;  in 
the  hitler  method  the  tenotome  is  introduced  through  the  conjunctiva  and  carried 
over  the  infra-orbital  margin  ;  it  is  best  to  expose  the  infra-orbital  nerve  by 
turning  up  a  flap  from  the  face,  when  a  portion  of  the  nerve  can  be  removed. 
The  nerve  being  exposed  and  freed  at  its  point  of  exit,  a  slightly  curved  or 
hooked  knife  can  be  entered  close  to  the  external  canthus  just  below  the  outer 
palpebral  ligament,  and  passed  backward  along  the  floor  of  the  orbit  toward 
the  apex,  and  along  the  anterior  border  of  the  spheno-maxillary  fissure,  which 
is  crossed  by  the  nerve  at  about  an  inch  behind  the  orbital  margin.  The 
knife  is  then  carefully  withdrawn,  and  the  nerve  divided  as  it  enters  the  infra- 
orbital  canal.  Traction  is  then  made  upon  the  peripheral  end  of  the  nerve  to 
remove  it  from  the  infra-orbital  canal.  Should  the  knife  be  carried  too  far  and  the 
spheno-maxillary  fossa  be  entered,  serious  hemorrhage  would  result. 

The  objections  to  this  last  method  are,  first,  the  hemorrhage  which  results 
from  the  division  of  the  infra-orbital  vessels  inaccessible  for  ligature;  second,  the 
uncertainty  of  accomplishing  the  division  of  the  nerve  ;  and  third,  in  many  of  these 
cases  the  posterior,  as  well  as  the  anterior,  dental  branches  are  involved  ;  if  this  be 
the  case,  removal  of  the  superior  maxillary  nerve  behind  Meckel's  ganglion  will  be 
required  in  order  to  insure  positive  relief. 

The  best  method  for  removing  the  superior  maxillary  nerve  through  the  face 
from  behind  Meckel's  ganglion  is  the  following:  Expose  and  free  the  infra-orbital 
nerve  at  its  exit  from  the  infra-orbital  foramen  ;  then,  with  a  three-quarter-inch 
trephine,  remove  a  button  of  bone  from  the  anterior  wall  of  the  antrum  of  High- 
more  ;  this  button  should  include  the  outer  wall  of  the  infra-orbital  foramen,  and 


SURGICAL    ANATOMY. 

in  removing  it  can1  must  lie  taken  not  to  sever  the  infra-orbital  nerve.  Open  the 
antruni  hy  tearing  through  the  lining  membrane,  and  then,  with  a  trephine  one- 
half  of  an  inch  in  diameter  or  with  a  small  chisel,  perforate  its  posterior  wall. 
This  opens  up  tin-  spheno-maxillary  fossa,  and  will  be  followed  hy  considerahle 
bleeding  from  wounded  brandies  of  tlie  internal  maxillary  vessels.  Before  pro- 
ceeding with  tlie  next  step  in  the  operation  pack  the  opening  in  the  posterior  wall 
with  sterile  gauze  to  cheek  the  hemorrhage;  then,  with  a  small  chisel,  break  away 
the  tloor  of  the  infra-orbital  canal  and  the  back  part  of  the  lloor  of  the  orbit  along 
the  roof  of  the  antruni  ;  this  permits  the  infra-orbital  nerve  to  be  drawn  down  into 
the  antruni,  when,  bv  making  slight  traction  upon  it,  a  pair  of  long,  slender  scissors, 
sharply  curved  and  with  blunt  points,  can  be  carried  along  the  nerve  through  the 
antrum,  and  the  superior  maxillary  nerve  divided  behind  Meckel's  ganglion.  In 
breaking  away  the  floor  of  the  infra-orbital  canal  the  infra-orbital  vessels  will  be 
torn,  but  the  bleeding  therefrom  is  of  no  serious  consequence  and  can  be  controlled 
by  packing  a  strip  of  sterile  gauze  into  the  broken  canal.  If  hemorrhage  persist 
after  the  removal  of  the  superior  maxillary  nerve,  the  spheno-maxillary  fossa  also 
may  be  packed  with  gauze,  which  should  protrude  through  the  opening  in  the 
anterior  wall  of  the  antrum.  The  gauze  may  remain  for  two  or  three  days  and 
serves  a  two-fold  purpose:  in  controlling  the  bleeding  and  in  favoring  drainage. 
The  operation  is  facilitated  by  the  use  of  an  incandescent  lamp  attached  to  a 
head-band. 

Clavus  (nail)  is  the  name  given  to  a  neuralgic  pain,  which,  from  its  intensity 
and  the  smallness  of  its  area,  is  likened  to  a  nail  being  driven  through  the  flesh 
and  bone.  It  generally  affects  hysteric  voting  women. 

It  is  not  inappropriate  for  the  author  to  say  here  that,  having  had  a  large 
experience  in  the  operative1  treatment  of  cases  of  trigeminal  neuralgia  (tie  doulou- 
reux), he  is  of  the  opinion  that  the  simpler  operative  procedure  should  first  be 
pursued,  for  the  period  of  relief  following  any  operation  is,  comparatively  speak- 
ing, lint  temporary  in  the  majority  of  cases.  This  is  not  in  accord  with  the  views 
of  some  of  the  leading  operators,  but  it  has,  nevertheless,  been  the  author's  experi- 
ence. He  has  operated  on  a  number  of  cases  several  times, — in  one  instance  as 
many  as  five, — each  operation  having  been  followed  by  relief  for  from  twelve  to 
eighteen  months.  The  peripheral  operations  may  be  repeated,  a  little  more  of  the 
nerve  being  removed  at  each  operation.  This  course  affords  the  patient  a  more 
prolonged  period  of  relief  than  could  be  obtained  by  first  performing  the  more- 
radical  operation.  As  a  last  resort,  the  most  radical  operation  of  all,  intra-cranial 
section  of  the  affected  nerve  or  removal  of  the  Gasserian  ganglion,  may  be  done. 
In  cases  where1  tlie  neuralgia,  has  returned  after  removal  of  the  superior  maxillary 
nerve  back  of  Meckel's  ganglion  by  opening  both  walls  of  the  antrum  anel  removing 


FACE.  r,<;.-> 

the  infra-orbital  nerve  from  its  canal,  Ilie  author  luis,  by  simply  cleaning  out  the 
track  of  the  original  wound,  seen  relief  follow. 

In  trifaeial  neuralgia  one,  two,  or  all  three  branches  of  the  trifaeial  nerve 
may  be  involved.  The  ophthalmic  division  supplies  the  skin  above  the  palpebral 
fissure;  the  superior  maxillary  division,  the  skin  between  the  palpebral  and  oral 
fissures,  including  the  temple;  the  inferior  maxillary  division  supplies  the 
skin  below  the  oral  fissure  as  far  as  the  hyoid  bone.  The  superior  and  the 
interior  maxillary  nerves  also  supply  the  teeth  through  their  branches,  while 
the  latter  supplies  the  anterior  two-thirds  of  the  tongue  through  its  lingual 
branch;  the  motor  root  of  the  third  division  also  supplies  the  muscles  of 
ma:  tie.-ition,  except  the  buccinator — /.  c.,  the  temporal,  rnasseter,  and  external 
and  internal  pterygoid  muscles.  Thus,  cunijilrt,'  jxirnl  ijxix  of  the  trifaeial  nerve 
abolishes  sensation  upon  one  side  of  the  fact'  and  on  top  of  the  head,  from 
the  highest  point  of  the  vertex  above  to  the  hyoid  bone  below  ;  laterally, 
to  and  including  the  front  of  the  ear  and  external  auditory  canal  and 
temple;  mesially,  the  anterior  nares  and  the  sensibility  as  to  touch  and  taste  of 
the  anterior  two-thirds  of  the  tongue,  besides  completely  paralyzing  the  muscles 
of  mastication  on  the  affected  side,  with  the  exception  of  the  buccinator.  Because 
of  the  insensibility  of  the  conjunctiva  the  lids  do  not  properly  protect  this  mem- 
brane, and  it  becomes  congested  and  inflamed,  a  condition  which  often  occurs 
spontaneously  through  implication  of  the  trophic  fibers  of  the  trifaeial  nerve.  At 
the  same  time  anterior  rhinitis  may  result  from  similar  causes,  or  may  be  excited 
by  the  discharge  of  the  conjunctival  secretion  into  the  inferior  nieatus  of  the  nose. 

Trifaeial  neuralgia  may  be  accompanied  by  active  implication  of  the  trophic 
filaments,  so  that  there  is  not  only  conjunctivitis  and  rhinitis,  but  vesicles  may 
form  upon  the  lips  and  anterior  nares.  This  should  be  borne  in  mind,  as  these 
trophic  nerve  disturbances,  when  overlooked,  may  be  the  source  of  much  per- 
plexity to  the  physician,  and  may  lose  him  a  desirable  patient. 

Paralysis  of  the  orbicularis  palpebrarum  muscle  also  leads  to  conjunctivitis, 
from  inability  to  close  the  eyelids ;  this  must  not  be  confounded  with  the  inflam- 
mation of  perverted  function  of  the  trophic  nerves. 

The  trophic  filaments  are  derived  from  the  sympathetic  nerve  ;  this  is  a 
general  rule  worth  remembering. 

The  entire  width  of  the  occiput,  as  high  up  as  the  vertex,  and  the  back  of  the 
pinna  are  supplied  by  the  occipitalis  major  nerve.  As  Hilton  pointed  out,  the 
pinna,  may,  therefore,  often  be  used  to  differentiate  between  spinal  and  cerebral 
central  nerve  disease  causing  neuralgia  ;  if  spinal,  the  back  of  the  pinna  is  affected 
and  the  front  is  not ;  if  cerebral,  the  signs  are  reversed. 

Reflex  or  referred  pains  are  frequent  in  the  area  of  distribution  of  the  trifaeial 


566  SURGICAL   . I. \.\T<) MY. 

nerve  because  nt'  llie  abundance  of  its  lilameiit>  and  tlioir  numerous  inosculations. 
Tbc  ])liysician  must,  therefore,  lie  ea refill  not  to  be  misled  by  tbe  location  of  pain, 
for  an  earache  may  lie  due  to  a  diseased  tooth,  as  was  the  case  in  a  patient  treated 
by  Hilton:  The  patient  had  consulted  several  leading  aurists  for  ,-i  persistent 
earache  without  obtaining  relief  except  from  the  use  of  anodynes;  the  ingenior.s 
Hilton  sagaciously  concluded  it  to  be  useless  to  treat  where  so  many  others  had 
(ailed,  and  looked  elsewhere  than  at  the  ear  for  the  cause  of  the  trouble.  This  he 
found  in  a  jagged  molar  tooth  which  was  continually  irritating  a  .small  nerve 
filament  at  the  bottom  of  an  ulcer  upon  the  side  of  the  tongue  adjoining  the  tooth. 
lie  advised  the  removal  of  the  tooth,  which  resulted  in  healing  of  the  ulcer  and 
in  cure  of  the  earache.  In  a  similar  manner  affections  of  any  filament  of  the 
trifacial  nerve  may  produce  pain  in  any  part  supplied  by  other  branches  of  the 
nerve. 

The  Lymphatic  Glands  of  the  Head  are  divided  into  a  superficial  and  a  deep 
set.  The  superficial  set  is  composed  of  the  occipital,  posterior  auricular,  parotid, 
buccal,  and  submaxillary  lymphatic  glands. 

The  occipital  or  suboccipital  lymphatic  glands  arc  situated  in  the  superficial 
fascia  along  the  superior  curved  line  of  the  occipital  bone  over  the  attachments  of 
the  trape/.ius  muscle  and  the  occipital  belly  of  the  occipito-frontalis  muscle.  These 
glands  receive  the  lymphatic  vessels  from  the  posterior  portion  of  the  scalp  or  that 
area  supplied  by  the  occipital  artery,  and  may  be  involved  in  erysipelas  or  other 
septic  conditions  of  the  posterior  portion  of  the  scalp.  The  efferent  vessels  from 
these  glands  empty  into  the  superficial  lymphatic  glands  of  the  neck. 

The  posterior  auricular  or  mastoid  lymphatic  glands  are  situated  behind  the 
pinna,  over  the  mastoid  process  and  the  insertion  of  the  sterno-mastoid  muscle. 
They  receive  the  lymphatic  vessels  from  the  posterior  auricular  region  and  the 
portion  of  the  scalp  above  it.  Their  efferent  vessels  empty  into  the  superficial 
lymphatic  glands  of  the  neck. 

The  parotid  lymphatic  glands  lie  upon  the  parotid  salivary  gland  in  front  of 
the  pinna,  below  the  zygoma,  and  a  few  are  found  in  the  substance  of  the  parotid 
salivary  gland.  They  receive  the  lymphatic  vessels  from  the  temporal  region,  the 
portion  of  the  scalp  above  it,  and  the  outer  portion  of  the  eyelids  and  of  the  cheek. 
Their  efferent  vessels  empty  into  the  superficial  lymphatic  glands  of  the  neck  and 
into  the  submaxillary  lymphatic  glands. 

The  buccal  lymphatic  glands  rest  upon  the  buccinator  muscle.  They 
receive  some  of  the  lymphatics  from  the  anterior  portion  of  the  face,  inner  half  of 
the  eyelids,  brow,  and  front  of  the  scalp.  Their  efferent  vessels  empty  into  the 
submaxillary  and  the  internal  maxillary  lymphatic  glands. 

The   submaxillary   lymphatic   glands   are   the   largest   group.      They   are 


FACE.  567 

situated  below  the  border  of  the  lower  jaw,  most  of  them  lying  in  tlie  submaxillary 
triangle  in  relation  with  tlie  submaxillary  salisary  gland  ;  two  or  tlnve  of  them 
(Mipra-hyoid  lymphatics)  lie  above  (he  body  of  the  hyoid  hone,  between  the  ante- 
rior bellies  of  the  two  digastric  museles.  The  subma  x  illary  ly  mphat  ie  glands, 
receive  the  lymphatic  vessels  from  the  front  of  the  >calp,  inner  part  of  the 
eyelids,  anterior  portion  of  the  face,  floor  of  the  mouth,  anterior  portion  of  the 
tongue,  snblingual  and  submaxillary  salivary  glands,  and  some  of  the  efferent 
vessels  from  the  parotid  lymphatic  glands.  Their  efferent  vessels  empty  into  the 
superficial  and  deep  cervical  lymphatic  glands. 

The  deep  lymphatic  glands  of  the  head  are  the  internal  maxillary,  lingual, 
and  post-pharyngeal  lymphatic  glands. 

The  internal  maxillary  lymphatic  glands  are  situated  in  the  pterygo-maxil- 
lary  region  :  some  are  in  relation  with  the  internal  maxillary  artery,  others  lie 
upon  the  posterior  portion  of  the  buccinator  muscle,  ami  still  other  deep  glands  lie 
upon  the  side  of  the  pharynx.  They  receive  the  lymphatic  vessels  from  the  orbi- 
tal, nasal,  temporal,  and  zygomatic  fossa1,  the  roof  of  the  mouth,  and  tlie  soft 
palate,  and  some  of  tlie  efferent  vessels  from  the  buceal  lymphatic  glands.  Their 
efferent  vessels  empty  into  the  deep  cervical  lymphatic  glands  and  partly  into  the 
deep  parotid  lymphatic  glands. 

The  lingual  lymphatic  glands  lie  upon  the  hyo-glossus  and  genio-hyo-glossus 
muscles.  They  receive  the  lymphatic  vessels  from  the  upper  surface  and  posterior 
part  of  the  tongue.  Their  efferent  vessels  unite  with  the  upper  glands  of  the  deep 
cervical  chain. 

The  post-pharyngeal  lymphatic  gland  is  situated  below  the  base  of  the  skull, 
between  the  posterior  wall  of  the  pharynx  and  the  rectus  eapitis  anticus  major 
muscle.  It  receives  the  lymphatic  vessels  from  the  upper  part  of  the  pharynx, 
part  of  the  nasal  fossa,  and  the  upper  part  of  the  prevertebral  museles. 

The  lymphatic  vessels  of  the  scalp,  which  drain  that  portion  behind  a  ver- 
tical line  passing  through  the  external  auditory  nieatus,  terminate  in  the  occipital 
and  posterior  auricular  lymphatic  glands ;  the  lymphatics  of  the  temporal  region 
of  the  scalp  and  that  portion  above  it  empty  into  the  superficial  and  deep  parotid 
lymphatic  glands;  the  lymphatic  vessels  of  the  frontal  region  of  the  scalp  follow 
the  frontal,  supra-orbital,  and  the  facial  veins  downward  over  the  face  to  the  sub- 
maxillary lymphatic  glands. 

The  lymphatic  vessels  of  the  face  are  divided  into  a  superficial  and  a  deep 
set.  The  superficial  lymphatics  of  the  anterior  portion  of  the  face — /.  e.,  of  the 
inner  half  of  the  eyelids,  of  the  nose,  lips,  and  anterior  part  of  the  cheek — pass 
downward  into  the  submaxillary  lymphatic  glands,  and  those  of  the  outer  half  of 


568  SURGICAL    ,1  \.\Tf >MY. 

the  eyelids  and  outer  part  of  the  check  Icrminnle  in  the  parotid  lymphatic  glands. 
The  </«ji  /i/nijiliiitii-K  i if  flu  J'i/ci — /'.  e.,  those  of  the  orbit,  part  of  the  nasal  fossa,  the 
hard  and  soft  palates,  deeper  portion  of  the  cheek,  temporal  fossa,  and  ptcrygo- 
maxillary  region — enter  the  internal  maxillary  lymphatic  glands. 

From  the  course  of  the  lymphatic  vessels  it.  follows  that  in  septic  conditions, 
such  as  infected  \voiinds,  erysipelas,  and  ahseess  of  the  posterior  portions  of  the 
scalp,  the  occipital  and  posterior  auricular  glands  may  become  affected, and  that  in 
the  same  condition  of  the  lateral  part  of  the  scalp  the  parotid  lymphatic  glands 
may  hecome  enlarged  or  inflamed,  and  septic  matter  from  the  frontal  region  of  the 
scalp  may  eventually  reach  the  suhmaxillary  lymphatic  glands.  The  course  of 
I  he  lymphatic  vessels  usually  corresponds  to  that  of  the  veins. 

Metastasis  from  carcinomatous  growths  generally'  follows  the  lymphatic 
vessels.  In  septic  conditions  or  caivinomata  of  the  anterior  portion  of  the  face,  of 
the  lips,  of  the  tongue,  and  of  the  snblingual  and  suhmaxillary  salivary  glands  the 
suhmaxillary  lymphatic  glands  hecome  enlarged.  Similar  affections  of  the  outer 
] ia rt  of  the  eyelids  and  face  involve'  the  parotid  lymphatic  glands;  and  in  corre- 
sponding conditions  of  the  orhital,  nasal,  temporal,  and  xygomatic  fosse,  of  the 
deeper  tissues  of  the  cheek  and  of  the  roof  of  the  mouth,  the  internal  maxillary 
lymphatic  glands  may  he  affected. 

Me  fore  dissect  ing  th:<  neck,  the  student  should  remove  the  brain  and  place  it 
in  a  solution  to  prepare  it  for  dissection  ;  he  should  study  the  diploic  veins,  the 
dura  mater  and  its  processes,  trace  the  meningval  vessels  and  the  sinuses,  and 
follow  the  cranial  nerves  to  their  respective  foramina  of  exit  from  the  cranial 
cavity.  These  structures  and  their  dissection  are  descrihcd  under  the  Membranes 
and  Vessels  of  the  Brain. 


THE  MEMIifiAXES  A XI)   VESSELS  OF  THE  BILIIX. 

DIS.SKCTIOX. — Before  removing  the  oalvaria,  or  skull  cap,  entire,  its  outer 
compact  tahle  should  bo  removed  on  one  side,  so  as  to  expose  the  diploe  or  middle 
tahle,  with  its  bony  channels  for  the  accommodation  of  the  diploic  vein-.  This  is 
most  readily  done  by  sawing  through  the  outer  table  in  the  horizontal  line 
described  in  the  removal  of  the  calvaria  as  a  whole,  and  in  the  sagittal  line  of 
the  skull,  when,  with  a  chisel,  it  can  be  lifted  off  piecemeal.  To  remove  the  por- 
tion below  the  line  of  the  horizontal  section  a  Hey's  saw  may  be  used. 

The  Diploic  Veins,  named  from  the  bones  in  which  they  ramify,  are  the 
frontal,  the  fronto-sphenoid,  the  fronto-parietal  (anterior  temporal),  the  external 
parietal  (posterior  temporal),  and  the  occipital  (parieto-occipital).  They  vary  greatly, 


PLATE  CXLVII. 


Anterior  temporal  diploic  v. 
Fronto-sphenoidal  diploic 
Frontal  diploic  v 


Frontal  sinus 


Occipital  diploic  v. 
Posterior  temporal  diploic  v 
Mastoici  foramen 


DIPLOIC  VEINS. 
569 


THE   MEMJiHAXES   AM>   VESSELS    <>!•'   THE    BRAIN.  571 

however,  in  diU'erent  subjects  (Merkel).  These  veins  arc  distinct  before  the  eranial 
hones  unite  with  one  another,  after  which  there  isa  I'rec  anastomosis  between  them. 
In  young  subjects  they  are  small,  but  they  increase  in  si/.c  as  age  advances (Quain). 
They  have  no  valves,  and  their  walls  are  exiivinelx  thin. 

The  frontal  veins  are  situated  in  the  anterior  part  of  the  frontal  hone:  they 
pass  most  frequently  through  the  sii]ira-orhital  foramen  and  empty  into  the  supra- 
orbital  vein  ;  they  may,  however,  empty  into  the  fronto-spheiioid  vein.  Yaricosity 
ot' this  vein,  even  to  the  extent  of  causing  absorption  of  the  outer  table  of  the  bone, 
may  occur. 

The  fronto-sphenoid  veins  lie  in  the  lateral  part  of  the  frontal  and  in  the 
sphenoid  bone:  they  empty  into  the  sinus  ahe  parva-. 

The  fronto-parietal  or  anterior  temporal  veins  are  situated  in  the  posterior 
part  of  the  frontal  and  in  the  anterior  part  of  the  parietal  bone  :  externally  they 
empty  into  the  deep  temporal  veins,  and  internally  into  the  superior  petrosal  sinus 
or  a  meiiingeal  vein. 

The  external  parietal  or  posterior  temporal  vein  is  situated  in  the  parietal 
bone  :  it  passes  through  a  foramen  in  the  posterior  inferior  angle  of  this  bone,  or 
through  the  mastoid  foramen  to  empty  into  the  lateral  sinus. 

The  occipital  or  parieto-occipital  vein,  the  largest  of  the  diploic  veins,  is  con- 
fined to  the  occipital  bone;  it  empties  externally  into  the  occipital  vein,  or  inter- 
nally into  the  lateral  sinus. 

In  compound  fractures  of  the  skull  the  diploic  veins  offer  an  opening  favor- 
able to  the  introduction  of  septic  matter  into  the  circulation,  thereby  permitting 
thrombosis  of  the  sinuses,  septic  meningitis,  general  sepsis  (pyemia),  or,  possibly, 
abscess  of  other  organs,  especially  the  liver.  The  diploic  veins  communicate  with 
those  of  the  scalp  by  means  of  very  small  vessels;  through  these  the  septic  matter 
may  be  conveyed  to  the  diploic  veins  and  thence  to  the  sinuses.  It  is  doubtless 
through  one  or  more  of  these  emissary  veins,  in  the  majority  of  cases,  that  septic 
material — the  result  of  inflammation  of  the  scalp — enters  the  venous  system. 

DISSECTION. — Remove  the  calvaria  (skull  cap)  by  sawing  through  the  outer 
and  middle  tables  along  a  line  carried  horizontally  around  the  skull,  connecting  a 
point  one-half  of  an  inch  above  the  supra-orbital  margin  with  a  point  the  same 
distance  ahove  the  external  occipital  protuberance;  then,  with  a  chisel  and  mallet, 
cut  through  the  inner  table,  prying  the  calvaria  from  the  underlying  dura  mater. 
In  breaking  through  the  inner  table  the  mallet  and  chisel  are  preferred  to  the 
saw,  there  being  less  danger  of  cutting  the  dura  mater:  even  when  closely  adhe- 
rent to  the  calvaria,  the  dura  mater  should  only  be  divided  as  a  last  resort.  In 
dividing  the  bone  in  the  temporal  region  its  thinness  must  be  borne  in  mind, 
otherwise  the  brain,  as  well  as  the  dura  mater,  may  be  injured. 


572  SURGICAL   ANATOMY. 

Pacchionian  bodies. — The  outer  surface  nf  the  dura  mater  being  exposed  by 
removal  of  the  skull  cap.  it  appear-  rough,  especially  along  the  lines  of  the  sutures 
••iiid  in  the  neighborhood  of  the  foramina,  where-  it  is  moM  closely  attached  to  the 
IIOIK-.  The  anterior  and  posterior  branches  of  the  middle  meningeal  artery,  with 
the  corresponding  veins,  will  be  seen  to  r;iiuifv  upon  the  dura  mater  over  each 
hemisphere;  in  most  instances  granular  masses,  (he  1'acchionian  bodies,  which  are 
villous  processes  of  the  arachnoid,  will  he  observed  upon  the  surface  on  each  side 
of  the  middle  line.  The  position  of  these  bodies  should  be  carefully  noted,  and 
they  must  not  be  regarded  as  pathologic  when  seen  on  the  operating  or  postmortem 
table.  In  some  cases  they  are  <|uite  large:  the  author  has  known  one  to  be  so 

large  as  t jcasion  sufficient  pressure  to  give  rise  to  focal  (Jacksonian)  epilepsy ; 

the  patient  was  trephined,  and  the  enlarged  1'acchionian  body  with  the  underlying 
cerebral  cortex  removed,  in  the  belief  that  it  was  a  neoplasm.  The  convulsions  were 
arrested  temporarily,  but  returned  after  a  time:  this,  unfortunately,  occurs  in  the 
majority  of  cases  of  Jacksonian  epilepsy  operated  upon.  These  bodies  are  always 
impressed  upon  the  oalvaria,  so  that  depressions,  corresponding  in  size  to  the  bulk 
of  the  bodies  causing  them,  may  be  seen  upon  each  side  of  the  median  line  of  the 
skull;  at  times  they  almost  perforate  the  bone.  As  a  rule,  they  hollow  the  bone 
out  sulliciciitly  to  render  it  translucent.  The  existence  of  these  bodies  may,  there- 
fore, be  ascertained  by  inspection  of  the  interior  of  the  oalvaria,  and  it  is  even  pos- 
sible, by  the  aid  of  transmitted  light,  to  determine  their  presence  by  examining 
from  without.  The  Pacchionian  bodies,  as  previously  slated,  are  processes  of  the 
arachnoid,  and  serve  as  channels  for  the  passage  of  the  cerebro-spinal  fluid  into  the 
venous  sinuses  of  the  dura  mater;  in  this  way  they  relieve  intra-cranial  pressure. 
They  vary  greatly  in  si/<-  in  different  persons,  and  in  children  are  quite  small. 

The  dura  mater,  the  most  external  of  the  three  membranes  of  the  brain,  forms 
the  internal  periosteum  of  the  skull,  and  affords  an  excellent  protection  to  the 
brain.  Through  the  medium  of  this  internal  periosteum  the  bones  of  the  skull 
receive  the  greater  part  of  their  nourishment;  this  explains  why  they  seldom 
necrose  in  scalp  wounds  in  which  the  pericranium  or  external  periosteum  is  torn 
away.  The  dura  mater  is  a  dense,  tough,  inelastic,  fibrous  membrane.  It  is  inti- 
mately adherent  to  the  base  of  the  skull,  'owing,  partly,  to  the  numerous  foramina 
found  there;  therefore,  extra-dural  extravasations  or  collections  of  blood  or  pus 
between  the  dura  and  skull  rarely,  if  ever,  occur  at  the  base  of  the  skull  ;  at 
the  sides  and  roof  of  the  cranial  cavity,  however,  where  the  membrane  is  com- 
paratively loosely  attached  (except  along  the  sutures  and  around  the  foramina), 
purulent  collections  and  extravasations  from  rupture  of  one  or  both  branches 
of  the  middle  meningeal  artery  are  not  uncommon.  These  conditions  cause 
compression  of  the  brain,  the  symptoms  of  which,  coming  on  immediately  after 


PLATE  CXLVIII, 


Orifice  of  superior  cerebral  v 

Dura 


Frontal  Sinuses 


Mat 


Arachnoid 

Dura  Mater 


Middle 
meningeal  a 


Pacchionian  bodies 


Superior  cerebral  v. 
Superior  longitudinal  sinus 


DURA  MATER,  ARACHNOID,  AND  MENINGEAL  VESSELS. 
573 


y///;  .i//;.]//;/,'.i.\7-;s  A\J>  VI-WELS  OF  THE  BRAIX.  575 

an  injury  to  the  head,  indicate  depressed  fracture:  it'  they  appear  a  short  tinu' 
then-after,  hemorrhage  :  some  days  after,  pus.  Tillaux  lias  demonstrated  that 
the  dura  mater  is  less  firmly  attached  to  the  t-emporal  t'ussa.  the  most  l're([Uent 
site  of  extra-dural  hemorrhage,  than  to  any  other  portion  of  the  interior  of  the 
skull  (Treves).  It  is  most  closely  adherent  to  the  hone  in  infancy  and  old 
age.  It  has  been  demonstrated  by  Sir  Charles  Hell  that  the  dura  mater  may 
he  separated  from  the  vault  and  sides  of  the  skull  by  striking  the  head  of  a 
cadaver  a  hard  blow  with  a  heavy  mallet. 

Extra-dural  hemorrhage. — The  most  common  canse  of  extra-dural  hemorrhage 
is  rupture  of  the  branches  of  the  middle  meningeal  artery;  this  is  usually  associ- 
ated with  fracture  of  the  parietal  bone  at  its  anterior  inferior  angle,  the  site  of  the 
groove  through  which  the  anterior  branch  of  the  artery  passes.  The  author  has 
trephined  for  compression  of  the  brain  produced  by  an  extra-dural  clot  not  asso- 
ciated with  fracture.  The  next  most  frequent  source  of  extra-dural  hemorrhage  is 
the  lateral  sinus. 

Attachments  of  the  dura  mater.- — Hesides  being  closely  adherent  to  the  base 
of  the  skull,  the  dura  mater  is  continuous,  through  the  optic  foramen,  with  the 
periosteum  of  the  orbit;  through  the  foramen  magnum,  with  the  dura  mater 
of  the  spinal  canal  ;  and  through  the  lissnres  and  the  various  foramina  through 
which  the  vessels  and  nerves  enter  and  leave  the  cranial  cavity,  clothed  by 
prolongations  of  this  membrane,  with  the  pericranium.  As  the  dura  mater  is 
directly  continuous  with  these  various  structures,  it  can  be  readily  understood 
how  inflammation  may  extend  by  continuity  into  the  cranial  cavity  and  cause 
secondary  meningitis. 

Pulsations  of  the  dura  mater. — The  dura  mater,  when  exposed  in  the  living 
subject,  may  present  two  distinct  pulsations,  communicated  from  the  underlying 
brain  :  one  synchronous  with  the  pulsation  of  the  arteries,  the  other  with  respira- 
tion, rising  in  expiration  and  sinking  in  inspiration. 

Layers  of  the  dura  mater. — The  dura  mater  consists  of  two  layers  :  an  outer, 
the  endosteal,  and  an  inner,  the  meningeal;  the  latter  is  lined  by  endothelium, 
which  gives  it  its  shiny  appearance.  Between  the  two  layers  venous  channels  or 
sinuses  and  the  (Jasserian  ganglion  are  found.  The  inner  or  meningeal  layer 
-ends  in  partitions  which  separate  and  support  the  different  portions  of  the  brain. 

Sarcomata  of  the  dura  mater  may  protrude  through  the  bones  of  the  cranium 
and  cause  a  swelling  in  the  scalp. 

DISSECTION. — Preliminary  to  removing  the  brain,  and  in  order  to  obtain  the 
most  correct  idea  of  the  normal  relations  of  the  two  larger  partitions  formed  by  the 
inner  layer, — namely,  the  falx  cerebri  and  the  tentorium  cerebelli, — divide  the 
dura  mater  in  the  following  manner:  Carry  two  incisions  through  it  from  before 


576  SI-J!H/r,\i.    ANATOMY. 

backward,  one-half  of  an  inch  on  cadi  side  of  tin-  median  lino,  thus  avoiding  the 
superior  longitudinal  sinus.  From  the  center  of  those  incisions  carry  a  transverse 
incision  upon  eaoli  side  as  far  as  the  divided  margin  of  the  hone.  Ueilect  the  Haps 
thus  made,  and  with  the  lingers  gently  sejmrate  the  hemispheres  of  the  cerebrum. 
The  falx  eerohri,  with  the  veins  from  the  surface  of  the  eeivl>nim  which  empty  into 
(lie  superior  longitudinal  sinus,  may  then  be  seen.  The  tontorium  cerelielli  can 
no\v  lie  readily  exposed  hy  lifting  up  the  posterior  extremities  of  the  hemi- 
spheres of  the  cerelinun  (occipital  lobes).  Next  lay  open  the  superior  longitudinal 
sinus  and  inspect  its  interior.  The  small  openings  of  the  veins  from  the  top  of 
the  hemispheres  (superior  cerebral  veins),  the  diploe,  and  the  dura  mater  will  be 
seen  along  its  entire  course  :  they  generally  enter  from  behind  forward.  Divide 
the  anterior  uncut  portion  of  the  dura  mater,  and  sever  the  falx  eorebri  from  its 
attachment  to  the  crista  galli,  along  with  the  veins  which  empty  into  the  superior 
longitudinal  sinus  ;  together  with  the  falx  cerebri  turn  back  the  strip  of  dura 
mater  in  which  is  contained  the  superior  longitudinal  sinus. 

Removal  of  the  brain. — The  brain  should  now  be  removed  in  the  following 
manner : 

Draw  the  subject  well  up  so  that  the  head  will  hang  over  the  edge  of  the  table. 
With  the  lingers  of  the  loft  hand  lift  the  frontal  lobes  of  the  cerebrum  from  the 
anterior  cranial  fossa  and  raise  the  olfactory  bulbs  from  the  cribriform  plate  of  the 
ethmoid  bone,  thus  severing  the  olfactory  nerves.  The  optic  nerves  with  the  oph- 
thalmic arteries  beneath  will  now  be  seen,  and  both  should  be  cut  across  (preferably 
with  scissors),  a  short  distance  from  the  brain.  By  gently  lifting  and  displacing  the 
hemispheres  backward,  the  infernal  carotid  arteries  and  the  infundibulum  (a  pro- 
cess of  gray  matter  which  connects  the  pituitary  body  with  the  tuber  cinereum)  will 
be  seen.  These  should  next  be  divided  or  the  artery  should  be  severed  and 
the  pituitary  body  removed  from  the  pituitary  fossa  after  incising  the  diaphragma 
sellre.  The  third  pair  of  cranial  nerves,  the  oculo-motor,  will  be  seen  lying 
behind  the  anterior  clinoid  processes  on  their  way  to  reach  the  cavernous  sinuses. 
Divide  those  nerves  and  then,  turning  the  head  to  the  right,  lift  the  temporo- 
sphenoid  lobes  from  the  middle  cranial  fossa,  and  the  tentorium  cerebelli  will 
be  brought  into  view.  This  should  be  cut  through  close  to  its  attachment  to 
the  posterior  clinoid  process  and  to  the  petrous  portion  of  the  temporal  bone. 
The  pathetic,  or  fourth,  and  the  trifacial,  or  fifth,  pairs  of  cranial  nerves  should 
be  severed  on  the  left  side  ;  turn  the  head  to  the  left,  and  divide  the  corresponding 
structures  on  the  right  side.  Bring  the  face  back  to  the  middle  line,  draw  the 
brain  well  backward,  and  divide  the  following  structures  from  within  outward 
in  the  order  named  :  The  abducens  or  sixth,  the  facial  or  seventh,  the  audi- 
tory or  eighth,  the  glosso-pharyngeal  or  ninth,  the  pneumogastric  or  vagus  or 


37 


PLATE  CXL1X, 


Veins  of  Galen 


Straight  sinus 


Middle  meningeal  a. 


Inferior  longitudinal  sinus 


Falx  cerebrl 


Superior  longitudinal  sinus 


Falx  cerebell 


Lateral  sinus 


Tentorium  cerebeMi 


Inferior  petrosal  sinus 


Nasal  septum 


Circular  sinus 


Transverse  sinus 


SINUSES  AND  PROCESSES  OF  DURA  MATER. 
578 


PLATE  CL 


Optic  n 

6th  n 


Motor  oculi  n 

4th  n 


Opthalmic  division  of  5th  n. 
Superior  maxillary  n. 
Gasserian  ganglion 
Inferior  maxillary  n. 


Foramen  caecum 
rCrista  galli 

Pituitary  body 
Circular  sinus 

^Internal  carotid  a, 
Opthalmic  a. 

,Cavernous  sinus 

.Middle  meningeal  a. 

Superior  petrosal  sinus 


5th  n 


Lateral  sinus 
Sigmoid  sinus 
Inferior  petrosal  sinus 
Transverse  sinus 
Basilar  plexus 
Occipital  sinus 
Superior  longitudinal  sinus 


SINUSES  AND  CRANIAL  NERVES. 
579 


THE  MEMBRANES  AND  VESSELS   OF  THE  JWALV.  581 

tenth,  the  spinal  accessory  or  eleventh,  and  the  hypo-glossal  or  twelfth  pair  of 
cranial  nerves.  The  next  and  iinal  step  consists  of  carrying  a  scalpel  down  into 
the  spinal  canal  as  far  as  possible  and  cutting  through  the  spinal  cord,  the  two 
vertebral  arteries,  and  the  spinal  portions  of  the  spinal  accessory  nerves.  The 
fingers  of  the  right  hand  should  then  be  slipped  beneath  the  cerebellum  and  pons, 
and  the  brain  removed. 

Preservation  of  the  brain. — If  the  brain  be  not  dissected  at  once,  it  should  be 
placed  in  a  solution  of  chlorid  of  zinc,  in  alcohol  and  formaldehyd,  or  Miiller's 
fluid.  If  placed  in  the  zinc  solution,  the  pia  mater  should  be  removed  later,  for  if 
allowed  to  remain  in  this  solution  for  some  time,  it  is  more  easily  separated  than 
in  the  fresh  condition.  If  alcohol  alone  be  used  to  preserve  the  brain,  the  pia 
mater  must  be  removed  before  placing  it  therein  ;  this  is  most  readily  done  under 
water  ;  but  if  preserved  in  alcohol  and  formaldehyd,  the  membrane  may  be  removed 
at  leisure.  Brains  hardened  in  chlorid  of  zinc  should  afterward  be  kept  in  alcohol. 
When  the  brain  has  been  removed  from  a  subject  injected  (embalmed)  with  chlorid 
of  zinc,  the  pia  mater  can  at  once  be  separated  and  the  brain  placed  in  alcohol. 
If  the  brain  from  a  fresh  subject  be  immediately  placed  in  alcohol,  subsequent 
removal  of  the  pia  mater  will  be  found  almost  impossible  on  account  of  its  firm 
adherence.  If  the  pia  mater  is  not  removed,  the  study  of  the  convolutions  is 
much  less  satisfactory.  Brains  which  have  been  hardened  in  chlorid  of  zinc  and 
afterward  kept  in  alcohol  are  much  easier  to  handle  than  when  kept  in  zinc  alone, 
as  the  latter,  by  its  action  on  the  skin,  makes  the  fingers  sticky.  Brains  preserved 
in  alcohol  and  formaldehyd  are  preferable  to  those  preserved  in  a  solution  of  zinc 
chlorid  and  alcohol,  because  they  are  not  shrunken  so  much  as  the  latter.  Brains 
taken  from  a  subject  embalmed  with  zinc  chlorid  should  be  hardened  in  a  solution 
of  the  same  ;  only  fresh  brains  should  be  hardened  and  preserved  in  alcohol  and  a 
two  per  cent,  solution  of  formaldehyd. 

Processes  of  the  dura  mater. — The  dura  mater,  through  duplication  of  its 
inner  or  meningeal  layer,  sends  three  larger  and  five  smaller  partitions,  folds,  or 
processes  into  the  cavity  of  the  skull  and  between  certain  divisions  of  the  brain  ; 
these  afford  support  to  the  latter.  The  three  larger  processes  are  the  falx  cerebri, 
the  tentorium  cerebelli,  and  the  falx  cci-clx-lli.  The  five  smaller  processes  or  folds 
comprise  two  pairs  and  a  single  one.  Of  the  two  pairs,  the  larger  are  attached  to 
the  lesser  wings  of  the  sphenoid  bone  and  project  into  the  Sylvian  fissure.  The 
smaller  pair,  crescentic  in  shape,  are  attached  to  the  clinoid  processes  and  over- 
hang the  optic  nerves.  The  single  fold  of  the  smaller  group  stretches  across  the 
pituitary  fossa  covering  the  pituitary  body,  and  is  known  as  the  diaphragm  of  the 
pituitary  fossa,  or  diaphragma  sellse.  Its  center  contains  an  opening  for  the  passage 
of  the  infundibulum. 


582  SURGICAL   ANATOMY. 

The  falx  cerebri  is  a  sickle-shaped  process,  narrowed  almost  to  a  point  in  front. 
where  it  is  attached  to  the  erista  galli  ;  it  is  broad  hehind,  where  it  is  attached  to 
the  middle  of  the  upper  surface  of  the  tentoriuin  cerebclli.  Jt  projects  into  ihe 
great  longitudinal  fissure  of  the  brain  and  separates  ihe  hemispheres  of  the  cere- 
brum. Its  convex  upper  border  is  attached  upon  the  inner  surface  of  the  calvaria 
to  the  edges  of  the  groove  which  accommodates  the  superior  longitudinal  sinus. 
The  concave  lower  border  is  free,  arches  over  the  corpus  callosum.  and  contains 
the  inferior  longitudinal  sinus. 

The  tentorium  eerebelli  is  a  somewhat  triangular-shaped  process,  having  its 
base  attached  upon  the  inner  surface  of  the  occipital  bone  to  the  edges  of  the  groove 
for  the  lateral  sinuses  ;  the  sides  are  attached  to  the  line  of  junction  of  the  upper 
and  posterior  surfaces  of  the  petrous  portion  of  the  temporal  bone,  from  the 
apex  of  which  they  a  re  continued  to  the  posterior  and  anterior  clinoid  processes. 
The  apex  corresponds  to  the  free  edge,  which  forms  the  lateral  and  posterior  boun- 
daries of  the  triangular  opening  known  as  the  tuijifrior  nrri/iitiil  J'oriinn  n  nr  mijtrriur 
fiti'iin a  n  IIKII/IIIIIII.  This  foramen  gives  passage  to  the  crura  eerebri,  the  superior 
peduncles  of  the  cerebellum,  the  oculo-motor  and  pathetic  nerves,  and  the  basilar 
artery.  The  tentorium  eerebelli  projects  into  the  great  transverse  fissure  of  the 
brain  ami  separates  the  posterior  lobes  of  the  cerebrum  from  the  cerebellum.  In 
the  convex  border  of  the  base  of  the  tentorium  eerebelli  the  horizontal  portions  of 
the  lateral  sinuses  are  contained  ;  in  the  sides,  the  superior  petrosal  sinuses  ;  and 
in  the  middle,  at  its  union  with  the  falx  cerebri,  the  straight  sinus.  The  base  of 
the  falx  cerebri  is  attached  along  the  entire  median  line  of  the  upper  surface 
of  the  tentorium  eerebelli,  and  the  falx  eerebelli  to  the  median  line  of  the  lower 
surface.  The  tentorium  serves  to  support  the  posterior  lobes  of  the  cerebrum, 
thus  protecting  the  cerebellum  from  pressure. 

The  falx  eerebelli  is  a  small,  vertical  fold  attached  posteriorly  to  the  internal 
occipital  crest  or  inferior  vertical  limb  of  the  occipital  cross,  and  above  to  the  under 
surface  of  the  tentorium  ce rebel li  :  it  is  situated  between  the  hemispheres  of  the 
cerebellum.  In  its  posterior  border  is  contained  the  occipital  sinus.  This  border 
at  times  splits  into  two  parts,  which  are  attached  to  the  sides  of  the  back  part  of 
the  foramen  magnum. 

Sinuses  of  the  dura  mater. — The  sinuses  of  the  dura  mater  are  venous  chan- 
nels formed  by  the  separation  of  its  endosteal  and  meningeal  layers,  and  are  lined 
by  a  prolongation  of  the  lining  membrane  of  the  veins.  They  are  rigid  tubes, 
which  always  remain  patent  (Macewen) ;  their  function  is  to  return  the  venous 
blood  from  the  brain  and  its  coverings,  the  diploe  (with  a  few  exceptions),  and 
also  the  greater  part  of  the  blood  from  the  orbit  and  eyeball.  They  collect  this 
blood  and  convey  it  to  the  jugular  or  posterior  lacerated  foramina,  where  it  is  taken 


THE  MEMBRANES  AND    VESSELS   OF  THE  BRA  IX.  583 

up  by  the  internal  jugular  veins.  There  are  sixteen  in  all,  and  they  consist  of 
two  groups:  those  situated  at  the  upper  and  haek  part  of  the  cranial  cavity,  and 
those  situated  at  the  base  of  the  skull.  The  former  group  includes  the  superior 
longitudinal,  the  inferior  longitudinal,  the  straight,  the  lateral,  and  the  occipital 
sinuses.  The  last-named  group  includes  the  cavernous,  the  sinuses  al;e  parv;e, 
the  circular,  the  superior  petrosal,  the  inferior  petrosal,  and  the  transverse.  They 
can  also  be  divided  into  a  median  and  a  lateral  group,  the  former  including 
the  single  sinuses,  situated  in  the  middle  line  of  the  skull,  and  the  latter  the 
paired  sinuses,  situated  on  both  sides  of  the  middle  line.  Five  are  in  pairs  and 
six  are  single.  The  five  pairs  are  the  lateral,  the  superior  petrosal,  the  inferior 
petrosal,  the  cavernous,  and  the  sinuses  alae  parvie.  The  six  single  sinuses  are 
the  superior  longitudinal,  the  inferior  longitudinal,  the  circular,  the  transverse, 
the  straight,  and  the  occipital.  Some  anatomists  describe  the  sigmoid  portions 
of  the  lateral  sinuses  as  an  additional  pair,  thus  making  the  number  eighteen. 

The  superior  longitudinal  sinus,  which  has  already  been  exposed,  occupies 
the  convex  border  of  the  falx  cerebri.  It  passes  from  the  foramen  ctceuni  at  the 
root  of  the  frontal  crest  through  the  mesial  groove  on  the  inner  surface  of  the  cal- 
varia  ;  deviating  slightly  to  the  right  in  the  posterior  part  of  its  course,  it  runs  to 
the  internal  occipital  protuberance,  to  end  in  the  torcular  Herophili.  The  Inmihir 
Hcmpldli  is  the  point  of  confluence  of  the  superior  longitudinal,  lateral,  straight, 
and  occipital  sinuses,  and  is  situated  a  little  to  the  right  of  the  internal  occipital 
protuberance.  The  superior  longitudinal  sinus  is  triangular  on  section,  the  base 
being  directed  toward  the  calvaria ;  it  is  narrower  in  front,  gradually  increasing  in 
width  as  it  passes  backward.  Its  lumen  is  crossed  by  a  number  of  fibrous  bands, 
the  chordae  WHIixii,  and  Pacchionian  bodies  are  frequently  found  projecting  into  it. 
It  receives  veins  from  the  scalp  through  the  parietal  foramina,  from  the  diploe,  the 
dura  mater,  and  the  hemispheres  of  the  cerebrum.  These  veins,  particularly  those 
from  the  cerebrum, — the  superior  cortical, — run  into  the  sinus  from  behind  forward 
in  the  direction  opposite  to  that  in  which  the  blood  current  passes ;  furthermore, 
they  pierce  the  wall  of  the  sinus  very  obliquely.  In  the  fetus  the  sinus  com- 
municates with  the  veins  of  the  nose  by  a  small  emissary  vein  which  passes 
through  the  foramen  cajcum,  but  this  seldom  occurs  in  the  adult.  The  superior 
longitudinal  sinus  presents  a  variable  number  of  lateral  outgrowths  or  pouches, 
which  have  been  named  the  lacunas  laterales.  It  is  into  these  that  the  Pacchi- 
onian bodies  project. 

Wounds  of,  and  line  for,  the  superior  longitudinal  sinus. — The  relation  of 
the  sinus  to  the  skull  renders  it  likely  to  be  wounded  in  compound  fracture  of  the 
vertex,  and  in  trephining  operations  over  the  median  line  of  the  vertex.  Hemor- 
rhage from  this  or  any  of  the  sinuses  is  best  controlled  by  plugging  with  sterile 


584  SURGICAL    .-I .Y.I  ToMY. 

gauze,  unless  the  wound  be  small,  iu  which  case  it  can  he  closed  hy  sutures.  The 
course  of  Hie  sinus  is  represented  on  the  scalp  hy  a  straight  line  drawn  from 
the  root  of  the  nose  over  the  median  line  of  the  vertex  to  the  external  occipital 
protuberance. 

Septic  or  infective  processes  of  the  scalp  may  enter  the  superior  longitudinal 
sinus  through  the  parietal  emissary  veins  ;  septic  processes  of  the  nose  may  reach 
that  sinus  through  the  vein  in  which  the  sinus  has  its.  origin. 

The  lateral  sinuses,  the  largest  of  the  cranial  sinuses,  extend  from  the 
internal  occipital  protuberance  to  the  jugular  foramina,  terminating  at  the  begin- 
ning of  the  internal  jugular  veins.  They  arise  on  each  side  of  the  internal 
occipital  protuberance,  across  which  they  are  connected  by  a  small  branch  ;  thence 
they  pass  outward  and  forward,  grooving  the  squamous  portion  of  the  occipital,  the 
posterior  inferior  angle  of  the  parietal,  the  mastoid  portion  of  the  temporal,  and 
the  jugular  process  of  the  occipital  bone.  Each  sinus  consists  of  two  portions,  a 
horizontal  and  a  sigmoid.  The  linrr.niiliil  /xir/io/i  is  situated  in  the  base  of  the 
tentoriuni  cerebelli ;  it  is  triangular  on  section,  the  base  of  the  triangle  being 
directed  toward  the  occipital  bone  and  the  posterior  inferior  angle  of  the  parietal 
bone.  The  nii/nmiiJ  jujiiinii  is  situated  below  the  tentoriuni  cerebelli,  and  grooves 
the  mastoid  portion  of  the  temporal  and  the  jugular  process  of  the  occipital 
bone;  it  is  seniicylindric  on  section,  and  is  considered  by  some  anatomists  a 
separate  sinus — the  sigmoid.  The  superior  petrosal  sinus  empties  posteriorly  into 
the  sigmoid  portion  of  the  lateral  sinus  at  its  origin.  The  lateral  sinus  varies 
somewhat  in  size  and  position,  a  fact  to  be  remembered  in  trephining  operations. 

Tri/n't'/i-iix  i if  tin  lufi rut  ximiK. — The  right  lateral  sinus  is  usually  larger  than 
the  left;  it  begins  at  the  torcular  Herophili,  and  is  the  continuation  of  the 
superior  longitudinal  sinus.  The  left  lateral  sinus  is  the  continuation  of  the 
straight  sinus.  In  addition  to  the  superior  petrosal  sinuses,  the  lateral  sinuses 
receive  emissary  veins  IVom  the  scalp,  which  pass  through  the  mastoid  and  pos- 
terior condyloid  foramina  ;  veins  from  the  diploe  (the  occipital  and  the  external 
parietal);  the  lateral  inferior  cerebral,  and  some  of  the  superior  and  inferior 
cerehellar  veins. 

Leeching. — A  suitable  site  for  applying  leeches  in  meningitis  is  behind  the 
ear;  in  this  way  blood  is  extracted  directly  from  the  lateral  sinus  through  the 
mastoid  emissary  vein,  thus  depleting  the  intra-craiiial  circulation.  Another,  but 
less  favorable,  location  for  the  application  of  leeches  in  meningitis  is  near  the 
inner  cauthus  of  the  eye,  where  the  angular  vein  anastomoses  with  the  ophthalmic 
vein. 

Thrombosis  of  the  lateral  sinus. — The  sigmoid  portion  of  the  lateral  sinus, 
or  thi'  sigmoid  sinus,  is  the  portion  of  the  intra-cranial  venous  circulation  most  con- 


PLATE  CLI. 


Bregma 


Lower  level: 
of  Cerebrum 


LINES  FOR  SINUSES. 
585 


Till':  M  !•:.}[  in;  A  \i-:s  AXD  iv-»7-;/.N  or  TUP:  BHAIX.  587 

cerned  in  disi',-i-rs  of  the  middle  car.  Thrombosis  of  this  portion  of  the  sinus  and 
of  tin-  commencement  (>!'  the  internal  jugular  vein  constitutes  one  of  the  complica- 
tions of  snppnrative  middle  ear  disease,  and  is  due  to  the  proximity  of  the  sinus 
to  the  middle  ear  and  mastoid  cells,  and  to  the  fact  that  veins  pass  directly  from 
the  mastoid  portion  of  the  temporal  hone  to  the  lateral  sinus.  This  condition 
demands  exposure  of  the  sinus  and  removal  of  the  clot;  this  is  hest  done  hefoiv 
general  systemic  infection  has  occurred.  When  sepsis  is  present  and  the  mastoid 
antrum  has  hecii  drained  by  trephining  the  mastoid  process  without  producing 
the  desired  ell'ect,  the  sigmoid  portion  of  the  lateral  sinus  should  he  exposed 
without  delay.  The  presence  of  a  clot  can  readily  he  determined  by  palpation ; 
removal  of  the  clot  should  immediately  he  followed  hy  antiseptic  packing  of  the 
sinus.  The  four  most  serious  complications  of  suppurative  otit is  media  are  septic 
thrombosis  of  the  lateral  sinus,  septic  meningitis,  abscess  of  the  temporo-sphenoid 
lobe  of  the  cerebrum,  and  ccrebellar  abscess. 

Infective  processes  may  also  reach  the  lateral  sinus  from  the  scalp  through 
the  mastoid  vein,  occipital  diploic  and  posterior  temporal  diploic  veins,  and 
through  the  superior  longitudinal  and  the  cavernous  sinus. 

Line  for  the  lateral  sinus.- — In  trephining  for  depressed  fracture  of  the 
occipital  bone,  ccivbellar  tumor,  cerebellar  abscess;  in  opening  the  mastoid  cells  or 
mastoid  antrum  ;  or  in  exposing  the  sinus  itself  in  septic  thrombosis,  it  is  highly 
important  to  bear  in  mind  the  relation  of  the  lateral  sinus  to  the  exterior  of 
the  skull.  Its  course  is  represented  as  follows:  Draw  a  line  from  the  external 
occipital  protuberance  to  a  point  an  inch  above  the  external  auditor}'  meatus.  The 
sinus  follows  this  line  as  far  as  the  base  of  the  mastoid  process ;  thence  it  runs 
downward  in  the  middle  line  of  the  mastoid  to  its  apex.  According  to  Macewcn, 
the  right  sigmoid  groove  is  generally  wider  and  deeper,  projects  farther  outward, 
and  reaches  farther  forward  .than  the  left  sigmoid  groove.  The  closer  proximity 
of  the  sigmoid  portion  of  the  right  lateral  sinus  to  the  middle  ear  perhaps 
explains  the  greater  frequency  of  Ultra-cranial  lesions  consecutive  to  right-sided 
otit  is  media. 

Operations  on  the  mastoid  process. — In  opening  the  mastoid  cells  or  mastoid 
antrum  it  is  better  to  expose  the  entire  surface  of  the  mastoid  process  by  turning  up 
a  large  flap,  than  to  expose  a  limited  surface  through  a  vertical  incision  behind  the 
ear  ;  this  is  particularly  the  case  if  the  disease  be  advanced,  when  the  overlying  soft 
parts  become  so  swollen  as  to  render  it  impossible  to  outline  the  process  with  any 
degree  of  certainty.  When  the  mastoid  process  is  exposed,  draw  two  lines — a  hori- 
zontal one  through  the  roof  of  the  external  auditory  meatus,  and  a  vertical  one 
through  its  posterior  wall.  In  adults  apply  the  trephine  or  gouge  at  a  point  a 
little  below  the  horizontal  and  behind  the  perpendicular  line  ;  in  children  apply 


588  SURGICAL   .-\\.\TOMY. 

the  instrument  at  a  point  directly  over  the  horizontal  and  behind  the  perpendicu- 
lar line.  With  the  trephine  or  gouge  make  an  opening  in  a  forward  and  inward 
direction.  Having  removed  the  external  table,  the  mastoid  antrnni  can  usually  be 
entered  with  a.  small  elevator  or  a  stilt'  director;  this  is  to  be  preferred  to  the 
trephine  or  goug«>,  as  it  lessens  the  risk  of  injuring  the  sigmoid  portion  of  the 
lateral  sinus.  Moth  the  tympanum,  or  middle  ear,  and  the  mastoid  cells  can 
be  drained  through  the  mastoid  aiitrum.  In  the  majority  of  cases  the  pus  is 
primarily  in  the  tympanum,  yet  occasionally  suppuration  takes  place  <il>  oriffine 
in  the  mastoid  cells.  It  must  not  be  forgotten  that  in  children  and  in  many 
adults  there  are  no  well-developed  mastoid  cells;  opening  directly  into  the  mastoid 
ant  rum  is,  therefore,  the  safest  course  to  pursue  in  all  cases. 

The  inferior  longitudinal  sinus  is  situated  in  the  free  concave  margin  of  the 
falx  cerebri.  It  is  of  small  size,  cylindric  on  section,  and  terminates  in  the  straight 
sinus  at  the  junction  of  the  falx  cerebri  with  the  anterior  margin  of  the  tentorium 
cerelielli  and  at  the  posterior  boundary  of  the  superior  occipital  foramen.  It 
receives  veins  from  the  falx  cerebri,  the  median  surface  of  the  cerebral  hemi- 
spheres, and  the  basilar  surface  of  the  frontal  lobes. 

The  straight  sinus  is  formed  by  the  union  of  the  inferior  longitudinal  sinus 
with  the  veins  of  Galen.  It  is  situated  at  the  junction  of  the  falx  cerebri  with  the 
tentorium  cerebelli,  and  terminates  at  the  internal  occipital  protuberance,  whence 
it  is  continued  as  the  left  lateral  sinus.  It  is  triangular  on  section  and  increases 
in  .size  as  it  passes  backward.  It  receives  veins  from  the  tentorium  cerebelli 
and  the  upper  surface  of  the  cerebellum  (the  superior  cerebellar).  Its  direction 
is  downward  and  backward. 

The  occipital  sinus  is  formed  by  the  union  of  two  small  veins  (marginal 
sinuses')  which  pass,  around  the  lateral  margins  of  the  foramen  magnum  and  com- 
municate with  the  sigmoid  portion  of  the  lateral  sinus  near  the  jugular  foramen 
and  with  the  posterior  spinal  veins.  It  passes  along  the  attached  margin  of  the 
falx  cerebelli  to  the  internal  occipital  protuberance,  where  it  empties  into  the  tor- 
cular  Herophili.  It  may  empty  into  one  of  the  lateral  sinuses  or  into  the  straight 
sinus.  It  receives  veins  from  the  tentorium  cerebelli  and  cerebellum,  communi- 
cating also  with  the  vertebral  veins  and  the  anterior  spinal  plexus. 

The  sinus  alae  parvae,  or  spheno-parietal  sinus,  one  of  the  paired  sinuses, 
occupies  a  groove  on  the  inferior  surface  of  the  lesser  wing  of  the  sphenoid  bone, 
and  runs  through  the  sphenoid  fold  of  the  dura  mater.  This  fold  is  attached  to 
the  base  of  the  lesser  wing  of  the  sphenoid  bone,  and  is  continuous  with  the 
dura  mater  at  its  attachment  to  the  anterior  clinoid  process.  It  empties  into 
the  cavernous  sinus,  and  often  receives  the  fronto-sphenoid  veins  of  the  diploi  us 
tributaries. 


'/'///•;   .I/A'.)//;  A'.iAV-.N   AM)    !7»7'.7,N    (>!•'    Till-:   BRAIN.  589 

The  cavernous  sinuses  are  situated  along  tlie  sides  of  the  body  of  the 
sphenoid  bone,  and  extend  from  beneath  the  anterior  clinoid  proeesses  to  the 
apices  of  the  petrous  portions  of  the  temporal  bones.  The  outer  wall  of  the  sinus 
— the  most  distinct — contains  the  third  and  fourth  nerves  and  the  ophthalmic 
division  of  the  fifth,  while  the  inner  wall  contains  the  internal  carotid  artery,  the 
sixth  nerve,  and  the  cavernous  plexus  of  the  sympathetic.  "Tillaux  alludes  to 
some  cases  of  aiieurysmul  communication  between  the  internal  carotid  artery  and 
the  sinus;  the  signs  of  such  lesion  are  dilatation  of  the  ophthalmic  vein  and  a  pul- 
satory swelling  behind  the  internal  angular  process  of  the  frontal  bone  "  (Owen). 
Tin1  endothelial  lining  membrane  of  the  sinus  prevents  the  blood  from  coming  into 
contact  with  the  nerves  and  artery.  Practically  speaking,  the  inner  wall  of  the 
sinus  does  not  exist  as  a  distinct  lamella,  hut  is  formed  by  the  structures  pre- 
viously enumerated  as  being  contained  therein.  Section  of  the  sinus  discloses 
numerous  bands  and  spaces  on  its  interior — hence  its  name.  The  nerves  which 
occupy  the  outer  wall  of  the  sinus  observe  I  lie  same  order,  both  from  above  down- 
ward and  from  within  outward,  in  which  they  have  been  mentioned.  <  )f  the 
structures  occupying  the  inner  wall,  the  sixth  nerve  is  the  most  external.  The 
sinus  receives  the  ophthalmic  vein  in  front,  and  the  sinus  ahe  parva>  above  the 
third  nerve.  It  communicates  with  its  fellow  by  means  of  the  circular  sinus,  and 
divides  posteriorly  (at  the  apex  of  the  petrous  portion  of  the  temporal  bone)  into 
the  superior  and  inferior  petrosal  sinuses.  It  receives  the  middle  cerebral  veins 
and  those  from  the  basilar  surface  of  the  frontal  lobe,  communicating  with  the 
pterygoid  plexus  of  veins  by  means  of  the  Vesalian  vein,  which  runs  through  the 
Yesalian  foramen  in  the  greater  wing  of  the  sphenoid  hone.  It  also  communicates 
with  the  internal  jugular  vein  through  the  venous  plexus  surrounding  the  petrous 
portion  of  the  internal  carotid  artery,  and  with  the  pterygoid  and  pharvngeal 
plexuses  of  veins  by  means  of  veins  which  run  through  the  foramen  ovale  and 
the  foramen  lacerum  medium. 

Infective  material  may  reach  the  cavernous  sinus  from  the  scalp  through  the 
supra-orbital  or  frontal  and  ophthalmic  veins,  and  through  the  fronto-sphenoid 
diploic  vein  and  the  sinus  ake  parvse  ;  from  the  orbit,  through  the  ophthalmic 
vein  ;  and  from  the  pterygo-maxillary  region  through  the  vein  of  Vesalius  and 
emissary  veins  which  pass  through  the  foramina  at  the  base  of  the  skull. 

Relations  of  the  cavernous  sinus  to  the  Gasserian  ganglion. — But  one  of  the 
cavernous  sinuses  should  be  opened  at  this  stage  of  the  dissection,  the  opening  of  the 
other  being  deferred  until  the  nerves  which  run  in  the  walls  of  the  sinus  to  enter 
the  orbit  have  been  traced.  Upon  opening  the  cavernous  sinus  it  will  be  seen  to 
occupy  an  interval  between  the  endosteal  and  meningeal  layers  of  the  dura  mater, 
as  is  the  case  with  the  other  sinuses.  In  this  interval  Meckel's  space,  which  is 


590  SURGICAL   ANATOMY. 

occupied  liy  the  (ia.-serian  ganglion,  may  also  l>r  demonstrated  at  this  time'.  The 
Comparatively  hit  i male  relation  existing  l)et\veen  the  sinus  and  the  ganglion  should. 
therefore,  be  home  in  mind  when  attempting  to  remove  the  ganglion  tor  relief 
of  trit'aeial  neuralgia,  otherwise  the  sinus  might  he  injured:  an  accident  of  this 
kind,  it  is  hardly  necessary  to  say.  might  he  serious. 

The  circular 'sinus,  through  which  the  two  cavernous  sinuses  communicate, 
surrounds  the  pituitary  hodv.  The  anterior  half  is  larger  than  the  posterior,  and 
in  advanced  life  is  larger  than  in  early  life.  At  times  one-hall'  is  absent.  It 
receives  veins  from  the  pituitary  hody  and  the  neighboring  hone  and  dura  mater. 

The  superior  and  inferior  petrosal  sinuses  arc  the  terminal  divisions  of  the 
cavernous  sinus.  The  superior  /"/V</W  x/^t.s  runs  in  a  small  groove  in  the  superior 
edge  of  the  petrous  portion  of  the  temporal  hone,  in  the  margin  of  the  tentorium 
cerebelli.  It  terminates  in  the  lateral  sinus  at  the  point  where  the  sigmoid  portion 
of  the  sinus  begins.  At  its  origin  it  is  crossed  by  the  fourth  nerve,  and  it,  in 
turn,  crosses  the  lifth  nerve.  It  receives  some  of  the  inferior  cerebral  and  superior 
ceivhellar  veins,  a  vein  from  the  middle  car  which  makes  its  exit  through  the 
petro-squamous  suture,  and  some  diploic  veins. 

The  inferior  jnfrnMil  xi/nis,  which  is  shorter  and  wider  than  the  superior,  runs 
in  the  groove  formed  by  the  junction  of  the  inferior  border  of  the  petrous  portion 
of  the  temporal  with  the  basilar  process  of  the  occipital  bone,  and  at  the  jugular 
foramen  empties  into  the  commencement  of  the  internal  jugular  vein.  The 
terminal  portion  of  the  inferior  petrosal  sinus  separates  the  glosso-pharyngeal  from 
the  pneumogastric  and  spinal  accessory  nerves.  It  receives  some  of  the  inferior 
ceivbellar  veins  and  some  from  the  medulla  oblongata  and  pons ;  veins  from  the 
internal  ear  which  make  their  exit  by  way  of  the  aqueductus  vestibuli  and 
aqueductus  cochlea?  also  empty  into  it. 

The  transverse  sinus,  through  which  the  inferior  petrosal  sinuses  commu- 
nicate with  each  other,  passes  across  the  basilar  process  of  the  occipital  bone.  It 
extends  inferiorly  as  far  as  the  anterior  margin  of  the  foramen  magnum,  where  it 
communicates  with  the  anterior  spinal  veins.  The  sixth  pair  of  nerves  pass 
through  it.  Some  authors  describe  the  transverse  sinus  as  a  plexus  of  veins 
(basilar  plexus). 

BLOOD  SUPPLY. — The  blood  supply  of  the  dura  mater  is  derived  from  the 
meningeal  arteries,  though  the  chief  function  of  these  vessels  is  to  supply  the  bones 
of  the  cranium.  These  arteries  comprise  practically  three  sets, — an  anterior,  a 
middle,  and  a  posterior, — and  in  the  dried  skull  their  course  can  readily  be  traced 
by  following  the  grooves  in  the  bones  which  they  occupy.  The  meningeal  arteries 
are  accompanied  by  relatively  small  veins. 

NKUVK  SUPPLY. — The  nerve  supply  of  the  dura  mater  is  derived  from   the 


THE  MEMJU:AM-:S  AXD  VESSELS  OF  THE  JIHAIX.  w\ 

Gasserian    ganglion,   the    lirst.   second,    and    third    divisions   of   the  trigemimil  or 
fifth,  the  pneumogastric,  tin.1  hypo-glossal,  and  tin-  sympathetic  nerves. 

DISSKI  TION. — Before  studying  tin'  courses  of  the  nieningeal  arteries,  which 
niM-ositates  stripping  the  dura  mater  from  the  skull,  examiiie  the  cranial  nerves 
as  they  pass  through  the  foramina  at  the  base  of  the  skull.  The  dura  mater 
should  then  he  disposed  of  in  the  foregoing  manner. 


INTRA-CRANIAL  COURSE   AND   MODE   OF   EXIT   OF   THE   CRANIAL 

NERVES. 

Coverings. — In  tracing  the  cranial  nerves  to  their  exit  through  the  foramina 
at  the  base  of  the  skull,  observe  that  each  pair  of  nerves  receive  investments  from 
all  three  membranes  of  the  brain.  The  coverings  derived  from  the  dura  mater 
and  the  pia  mater  are  continuous  with  the  sheaths  of  the  nerve,  while  that  from 
the  arachnoid  terminates  as  the  nerves  enter  the  dura  mater. 

Enumeration. — The  names  of  the  twelve  pairs  of  nerves,  mentioned  from 
before  backward,  are  :  The  olfactory,  the  optic,  the  oculomotor,  the  pathetic,  the 
trifacial,  the  abducent,  the  facial,  the  auditor}-,  the  glosso-pharyngeal,  the 
pneumogastric,  the  spinal  accessory,  and  the  hypo-glossal  nerves. 

The  olfactory  nerves,  the  first  pair,  consist  of  the  olfactory  tracts  and  bulbs, 
and  have  been  removed  with  the  brain  and  their  branches  divided.  Strictly 
speaking,  the  olfactory  bulb  and  tract  are  to  be  regarded  as  portions  of  the  brain. 
Arising  from  the  lower  surface  of  the  olfactory  bulb  are  some  twenty  filaments, — 
the  real  olfactory  nerves, — Avhich  are  arranged  in  two  rows,  an  inner  and  an 
outer.  They  supply  the  upper  portions  of  the  septum  and  the  outer  wall  of  the 
nose  respectively,  and  terminate  in  cells  in  the  mucous  membrane.  By  carefully 
separating  the  dura  mater  from  the  grooves  in  the  base  of  the  skull  on  each  side 
of  the  crista  galli,  these  real  olfactory  nerves  may  be  seen  running  through  the 
foramina  in  the  cribriform  plate  of  the  ethmoid  bone. 

The  optic  nerves,  the  second  pair,  pass  through  the  optic  foramina  accom- 
panied by  the  ophthalmic  artery. 

The  oculo-motor  nerves,  the  third  pair,  pierce  the  dura  mater  near  the  ante- 
rior clinoid  processes,  and  enter  the  outer  wall  of  their  respective  cavernous  sinuses. 
In  this  situation  they  lie  above  the  fourth  nerve  and  the  ophthalmic  branch  of  the 
fifth.  They  enter  the  orbits  through  the  sphenoid  fissures,  and  here  lie  below  the 
fourth  nerve  and  part  of  the  ophthalmic.  They  next  divide  into  two  branches, 
which  pass  between  the  heads  of  the  external  recti  muscles,  separated  from  each 
other  by  the  nasal  branches  of  the  ophthalmic  nerves ;  they  supply  all  the 
extrinsic  muscles  of  the  eyeball  with  the  exception  of  the  superior  oblique  and 


592  SURGICAL  ANATOMY. 

external  rectus,  and  also  supply  the  circular  muscular  fibers  of  the  iris  and  the 
ciliary  muscle. 

The  pathetic  nerves  (trochlearis),  the  fourth  and  smallest  pair  of  cranial 
nerves,  pierce  the  dura  mater  near  the  free  edge  of  the  tentorium  cerebclli,  a  little 
behind  the  posterior  clinoid  processes  and  above  the  oval  openings  for  the  liftli 
nerves.  Each  enters  the  outer  wall  of  its  respective  cavernous  sinus,  where  it 
lies  below  the  third  nerve  and  above  the  ophthalmic  nerve,  and  passes  into  the 
orbit  through  the  sphenoid  fissure,  in  which  it  lies  above  the  third  nerve  and 
the  ophthalmic  division  of  the  fifth.  It  supplies  the  superior  oblique  or  trodi- 
learis  muscle. 

The  trifacial  nerves,  the  fifth  pair,  have  two  roots, — a  larger  sensory  and  a 
smaller  motor, — and  pass  through  an  oval  opening  in  the  dura  mater  beneath  the 
free  border  of  the  tentorium  cerebelli.  Above  the  fifth  nerve  is  the  fourth  nerve, 
and  below  it  are  the  apex  of  the  petrous  portion  of  the  temporal  bone  and  the  inter- 
nal auditory  meatus.  Upon  the  larger  or  sensory  root  is  the  Gasserian  ganglion, 
which  can  not  be  seen  until  the  dura  mater  is  raised  from  the  base  of  the  skull. 
Its  description  will  therefore  be  deferred  until  this  has  been  done.  The  ophthalmic 
branch  of  the  trifacial  nerve  is  exposed,  and  is  seen  running  through  the  outer  wall 
of  the  cavernous  sinus,  where  it  lies  beneath  the  fourth  nerve.  It  divides  into  three 
branches, — the  lacrymal,  frontal,  and  nasal, — after  which  it  enters  the  orbit  by 
way  of  the  sphenoid  fissure.  In  the  wall  of  the  sinus  the  ophthalmic  branch  is 
joined  by  filaments  from  the  carotid  plexus  of  the  sympathetic  nerve,  communicat- 
ing with  the  third,  fourth,  and  sixth  nerves,  and  giving  off  a  recurrent  branch 
which  passes  backward  between  the  layers  of  the  tentorium  cerebelli. 

The  abducent  nerves,  the  sixth  pair,  pierce  the  dura  mater  behind  the  body 
of  the  sphenoid  bone  immediately  below  the  posterior  clinoid  processes,  and  pass 
through  the  transverse  sinus.  Each  then  courses  along  the  inner  wall  of  the  cav- 
ernous sinus  to  the  outer  side  of  the  internal  carotid  artery,  and  enters  the  orbit  by 
way  of  the  sphenoid  fissure,  lying  between  the  ophthalmic  vein  and  the  inferior 
branch  of  the  oculo-motor  nerve.  It  supplies  the  external  rectus  muscle,  between 
the  two  heads  of  which  it  passes.  Within  the  wall  of  the  cavernous  sinus  it  is 
joined  by  filaments  from  the  carotid  plexus  of  the  sympathetic  nerve. 

The  facial  nerves,  the  seventh  pair,  leaves  the  cranial  cavity  by  way  of  the 
internal  auditory  meatus.  Each  nerve  is  accompanied  by  the  pars  intermedia 
of  Wrisberg,  the  auditory  nerve,  and  the  auditory  artery.  At  the  bottom  of  the 
meatus  it  enters  the  facial  or  Fallopian  canal.  (For  a  description  of  the  course 
of  the  nerve  through  the  facial  canal  see  the  Dissection  of  the  Internal  Ear.) 
It  lies  within  the  meatus,  first  to  the  inner  side  of,  and  then  directly  over,  the 
auditory  nerve. 


Tin-:  .i//-:.i//,'/,'.i.\7>-  AND  VESSELS  or  TIIK  ni:.\i\.  593 

Tin-  auditory  nerves,  the  eighth  pair,  leave  tin-  cranial  cavity  through  the 
internal  auditory  incatuscs  in  company  with  the  auditory  arteries,  the  facial  nerves, 
ami  the  pars  intermedia.  Reaching  the  hutlnm  ul'  the  meatns  each  nervc>  divides 
into  two  1  mint-lies,  the  eorhlear  and  the  vestilmlar,  tor  the  supply  of  the  cochlea, 
the  veMibule,  ami  the  .semicircular  canals. 

The  glosso-pharyngeal  nerves,  the  ninth  pair;  the  pnetunogastric  (vagus), 
the  tenth  pair:  and  the  spinal  accessory,  the  eleventh  pair,  leave  the  cranial 
cavity  by  way  of  the  jugular  or  posterior  lacerated  foramen,  passing  through  its 
midtlle  compartment.  The  glosso-pharyngeal  nerves  have  a  separate  sheath  of 
dura  mater  and  arachnoid,  and  lie  in  front  of  tht>  pneumogastric  and  spinal 
accessory  nerves.  The  last-mentioned  two  have  a  sheath  of  dura  mater  common 
to  hoth,  hut  they  have  separate  sheaths  of  arachnoid.*  The  spinal  accessory  nerve 
is  made  up  of  t-wu  pails:  a  smaller  or  accessor;  portion  (accessory  to  the  pneuino- 
gastric  nerve),  which  runs  with  the  pnenmogastric.  and  a  spinal,  which  arises 
from  the  spinal  cord,  and  is  hy  far  the  larger  portion.  The  latter  enters  the 
cranial  cavity  through  the  foramen  magnum  and  joins  the  accessory  portion 
shortly  after  the  latter  emerges  from  the  medulla. 

The  hypo-glossal  nerves,  the  twelfth  pair,  leave  the  cranial  cavity  through 
the  anterior  condyloid  foramina. 

The  internal  carotid  artery. — When  the  cavernous  sinus  has  been  laid  open 
and  the  nerves  within  its  wall  exposed,  carefully  examine  the  internal  carotid 
artery  running  in  the  inner  wall  of  the  sinus  hefore  disturbing  the  dura  mater 
further.  After  its  exit  from  the  carotid  canal,  the  curves  which  the  artery  makes 
in  reaching  the  brain  can  now  be  seen  to  the  best  advantage.  Having  emerged 
from  the  carotid  canal  the  artery  turns  upward,  passing  toward  the  posterior 
clinoid  process.  It  next  runs  forward  through  the  inner  wall  of  the  sinus  to 
reach  the  inner  side  of  the  anterior  clinoid  process,  where  it  again  turns  upward 
and  pierces  the  dura  mater  on  the  inner  aspect  of  the  anterior  clinoid  process;  just 
before  piercing  the  dura  mater  it  gives  off  the  ophthalmic  branch.  The  cranial  or 
terminal  portion  thus  makes  two  bends,  which  give  it  the  shape  of  the  letter  S. 
Running  along  with  the  artery  and  external  to  it  is  the  abducent  (sixth)  nerve. 
The  lining  membrane  of  the  sinus  alone  separates  both  the  artery  and  the  nerve 
from  the  interior  of  the  sinus.  Within  the  walls  of  the  sinus  the  artery  gives  off 
branches  known  as  the  arteria?  receptaculi,  which  supply  the  walls  of  the  sinus, 
the  pituitary  body,  the  Gasscrian  ganglion,  and  the  dura  mater  (through  the 
anterior  meningeal).  It  is  surrounded  by  filaments  of  the  sympathetic  nerve 
which  form  two  plexuses,  the  carotid  on  the  outer  and  the  cavernous  on  the  inner 
side  of  the  artery.  The  former  plexus  communicates  with  the  abducent  nerve 
and  the  Gasserian  and  Meckel's  ganglia;  the  latter  communicates  with  the  oculo- 
38 


.V.M  SURGICAL    AXATOMY. 

motor,  pathetic,  and  ophthalmic  nerves,  and  Furnishes  the-  sympathetic  root  to  the 
ophthalmic  or  lenticular  ganglion. 

DISSKCTION. — The  dura  mater  should  now  lie  dissected  From  the  sides  and 
base  of  the  skull  ;  it  will  be  Found  closely  adherent  to  the  latter,  requiring  care  in 
its  removal  in  order  to  avoid  injuring  the  Following  structures:  The  ( lasserian 
ganglion,  the  superior  and  interior  maxillary  nerves,  which  are  branches  From 
tin-  ganglion,  the  In  rye  superficial  petrosal.  the  external  supcriicinl  petrosal 
when  present,  and  the  motor  root  of  the  trifacial  nerve.  The  last  and  the  large 
superficial  petrosal  nerve  run  beneath  the  ganglion. 

The  Gasserian  ganglion  occupies  a  depression  on  the  superior  surface  of  the 
petrous  portion  of  the  temporal  bone  near  the  apex,  and  rests  to  a  slight  extent  on 
the  cartilage  tilling  the  middle  lacerated  foramen.  It  holds  an  intimate  relation, 
therefore,  to  both  the  internal  carotid  artery  and  the  cavernous  sinus.  It  is  cres- 
ceiitic  in  outline,  its  concavity  being  directed  backward  and  its  convexity  forward 
and  outward,  and  it  measures  about  one-half  of  an  inch  in  width.  Its  upper  and 
lower  surfaces  are  slightly  convex.  It  occupies  an  interval  between  the  endosteai 
and  meningeal  layers  of  the  dura  mater  (Mirl:i-l'x  */w/<r),  and  for  this  reason  the 
endosteai  layer  of  the  dura  mater  must  be  divided  in  attempting  its  removal 
through  the  side  or  base  of  the  skull.  From  the  convexity  of  the  ganglion  arise 
the  ophthalmic,  superior  maxillary,  and  inferior  maxillary  nerves,  the  fust  two 
being  sensory  nerves  throughout.  The  inferior  maxillary  nerve  is  sensory  until  it 
reaches  the  outside  of  the  skull;  here  it  is  joined  by  the  motor  root  of  the  trifacial 
nerve,  which  leaves  the  cranial  cavity  with  it  by  way  of  the  foramen  ovnle ;  the 
inferior  maxillary  thus  becomes  a  mixed  nerve. 

The  superior  maxillary  nerve,  intermediate  in  size  between  the  ophthalmic 
and  the  inferior  maxillary,  leaves  the  cranium  by  way  of  the  foramen  rotundum. 

The  inferior  maxillary  nerve,  the  largest  branch  of  (ho  lifth,  leaves  the 
cranial  cavity  by  way  of  the  foramen  ovale  which  also  transmits  the  small  super- 
licinl  petrosal  nerve  and  the  small  meningenl  artery. 

Intra-cranial  neurectomy  of  the  superior  and  inferior  maxillary  nerves.— 
This  is  one  of  the  operations  for  relief  of  trifacial  neuralgia,  and  is  performed  in 
the  following  manner:  An  fl-shnped  flap  is  made  over  the  temporal  region. 
beginning  near  the  tragus  of  the  auricle  and  carried  upward  to  about  the  level  of  the 
temporal  ridge,  ending  near  the  external  angular  process  of  the  frontal  bone.  All 
the  structures  down  to  the  bone  are  divided.  They  include  the  skin  and  superficial 
Fascia,  the  attrahens  aurem  muscle,  the  temporal  branches  of  the  facial  and  anriculo- 
temporal  nerves,  the  anterior  and  posterior  temporal  arteries  and  veins,  the  occi- 
pito-frontalis  aponeurosis,  the  areolar  tissue  layer,  the  temporal  fascia  and  muscle. 
the  deep  temporal  vessels,  and  the  periosteum.  The  bone  is  then  cut  through  in 


THE  MEMBRAM-:*  A.\f>   n-SSELS   OF   THE   IlllMX.  :,'.).-, 

the  line  of  tin-  original  incision,  preferably  with  an  instrument  specially  con- 
structed  for  this  purpose.  Ciuvniust  l>c  taken  to  avoid  injuring  tlic  membrane- 
of  the  brain.  An  elevator  is  introduced  beneath  the  hone  after  it  has  been 
cut  through  along  the  whole  line  of  the  incision,  and  the  entire  flap  is  forced 
outward  and  downward.  The  bone  will  fracture  between  the  ends  of  the  oval 
incision  a  little  above  the  line  of  the  zygomatic  arch.  The  bone  and  soft 
structures  should  be  reflected  as  one  flap  in  thus  exposing  the  dura  mater  of  the 
brain.  When  the  middle  meningeal  artery  lies  in  a  canal  in  the  temporal  and 
parietal  bones,  it  may  be  torn  in  forcing  the  flap  downward.  This  necessitates 
tying  the  vessel  or  plugging  the  canal  for  the  vessel  with  gauxe,  as  the  bleeding 
would  be  severe.  The  dura  mater  is  separated  from  the  floor  of  the  middle  cranial 
fosaa,  and  when  the  brain  is  lifted  upward,  the  superior  and  inferior  maxillary 
divisions  of  the  fifth  or  trifacial  nerve  will  be  exposed.  As  much  as  ]x>ssible  of 
both  nerves  is  then  excised,  and  the  distal  ends  pushed  through  their  respective 
foramina  of  exit.  The  operation  is  completed  by  repositing  the  flap  of  bone,  sutur- 
ing the  soft  parts,  and  dressing  the  wound. 

Removal  of  the  Gasserian  ganglion. — In  removing  the  Gasserian  ganglion 
one  of  two  routes  can  be  selected,  either  through  the  side  of  the  skull  or  through 
its  base  :  the  latter  method  was  first  practised  by  Mr.  Rose.  In  the  former  method, 
by  far  the  most  preferable,  an  osteo-plastic  resection  of  the  side  of  the  skull  is 
made,  similar  to  that  in  the  previous  operation.  The  flap  of  bone  includes 
part  of  the  frontal,  greater  wing  of  the  sphenoid,  parietal,  and  the  squamous 
portion  of  the  temporal  bone.  After  the  superior  and  inferior  maxillary  nerves 
are  exposed,  they  should  be  traced  backward  to  the  Gasserian  ganglion ;  this 
is  lodged  in  a  depression  near  the  apex  of  the  petrous  portion  of  the  temporal 
bone,  in  a  space  (Meckel's)  situated  between  the  two  layers  of  the  dura  mater. 
The  outer  layer  of  the  dura  mater  should  be  incised,  and  the  ganglion  removed. 
The  inferior  and  superior  maxillary  divisions  of  the  trifacial  nerve  arc  then 
resected  up  to  their  point  of  exit  from  the  skull,  and  the  distal  ends  pushed 
through  their  respective  foramina.  The  inferior  maxillary  nerve  leaves  the 
skull  through  the  foramen  ovale ;  the  superior  maxillary  nerve  through  the  fora- 
men rotundum.  The  osteo-plastic  flap  is  then  replaced  and  the  wound  closed. 
The  final  steps  of  this  and  the  succeeding  operation  will  be  greatly  facilitated 
by  the  use  of  an  electric  headlight  attached  to  a  head-band. 

In  the  second  method  the  first  step  consists  of  dissecting  up  a  flap  of  skin, 
superficial  and  deep  fascia  from  the  side  of  the  face,  and  exposing  the  zygoma, 
taking  care  not  to  wound  the  parotid  duct.  The  zygoma  should  be  sawed 
through  at  each  end  and  turned  down,  along  with  the  masseter  muscle.  Next 
divide  the  coronoid  process  of  the  inferior  maxilla  and  turn  it  upward  with 


.V.ii;  SURGICAL   .\\AToMy. 

the  temporal  muscle;  this  exposes  the  internal  maxillary  artery  and  ptcrygoid 
muscles.  The  internal  maxillary  artery  should  he  tied  at  two  points  and 
divided.  The  external  ptcrygoid  muscle  should  then  he  carefully  detached  from 
its  origin,  thus  exposing  the  inferior  maxillary  nerve  as  it  emerges  from  the 
foramen  ovale,  which  is  the  point  at  the  hase  of  the  skull  to  he  attacked  with 
the  trephine.  If  the  inferior  maxillary  nerve  has  not  heeii  removed  hy  a 
previous  operation,  it  acts  as  an  important  guide  in  locating  the  foramen.  The 
eminentia  articiilaris  and  the  root  of  the  pterygoid  process  are  additional  guides. 
the  foramen  being  usually  just  in  front  of  a  transverse  line  drawn  through 
the  eminence,  and  immediately  hehind  the  root  of  the  external  pterygoid 
plate.  When  the  foramen  has  heen  clearly  exposed,  apply  a  small  trephine, 
one-half  of  an  inch  in  diameter,  to  the  hase  of  the  skull  and  remove  a  hntton 
of  hone  which  includes  the  margin  of  the  foramen.  The  proximity  of  the  fora- 
men to  the  carotid  canal  renders  this  step  a  very  important  one.  The  disc  of 
hone  having  heen  removed,  the  exposed  dura  mater,  which  bulge-  more  or  le-s 
into  the  trephine  hole,  should  he  opened  and  the  inferior  maxillary  nerve,  if  not 
already  exposed,  sought.  When  found,  it  is  traced  to  the  (lasserian  ganglion, 
which  is  then  removed  piecemeal.  The  operation  is  completed  hy  replacing  the 
tissues  in  as  nearly  the  normal  position  as  possible ;  the  zygoma  and  the  hone  on 
each  side  of  it  are  drilled  and  sutured,  drainage  is  introduced,  and  the  wound 
dosed.  The  hutton  of  bone  is  not  replaced.  Extreme  care  should  he  exercised 
throughout  this  operation,  which  is  one  of  great  magnitude.  The  nutrition  of 
the  eyeball  may  he  so  seriously  atlected  as  to  result  in  its  destruction. 

DISSKCTIO.X. — To  continue  the  dissection,  divide  the  larger  or  sensory  root  of 
the  trifacial  nerve,  lift  the  Gasserian  ganglion,  and  displace  it  forward  and  down- 
ward SD  as  to  better  expose  the  smaller  motor  root  and  the  large  superlicial 
petrosal  nerve,  both  of  which  lie  heiieath  the  ganglion.  The  motor  root  of  the 
trifacial  nerve  can  he  traced  to  the  foramen  ovale,  where,  with  the  inferior 
maxillary  nerve,  it  makes  its  exit  from  the  skull. 

The  large  superficial  petrosal  nerve  arises  from  the  geniculate  ganglion  of 
the  facial  nerve,  and  will  be  seen  emerging  from  the  hiatus  Fallopii.  Thence  it 
runs  in  a  small  groove  on  the  side  of  the  superior  surface  of  the  petrous  portion  of 
the  temporal  hone  to  reach  the  cartilage  which  fills  the  middle  lacerated  foramen. 
It  pierces  the  cartilage  and  is  joined  by  the  great  deep  petrosal  nerve  from  the 
carotid  plexus  of  the  sympathetic,  thus  forming  the  Vidian  nerve. 

The  small  superficial  petrosal  nerve  arises  from  the  facial  nerve,  emerges  from 
the  facial  canal  by  way  of  a  small  foramen  situated  external  to  the  hiatus  Fallopii, 
passes  to  the  foramen  ovale,  and  joins  the  otic  ganglion.  Occasionally  it  passes 
through  a  small- foramen  situated  between  the  foramina  ovale  and  spinosum. 


'/•///•:  .v  AM//;  A',  i. \7'>'  A.\D  ]V-»V-;/.N  or  TJII-:  iin.i/x.  597 

The  external  superficial  petrosal  nerve  leaves  the  facial  nerve  ami  canal  by 
way  of  a  small  foramen  placed  external  to  that  i'<>r  the  small  superticial  petrosal 
nerve,  on  its  way  to  join  the  plexus  of  the  sympathetic  upon  the  middle  meningcal 
artery.  This  nerve  is  seldom  found  in  the  dissection  of  the  interior  of  the  Imse  of 
the  cranium,  for  in  lifting  up  the  endosteal  layer  of  the  dura  mater  the  petrosal 
nerves  are  very  apt  to  he  severed  unless  the  utmost  care  is  observed. 

The  Meningeal  Arteries — the  {interior,  the  middle,  the  small,  and  the 
posterior  nieiiingeal — run  between  the  skull  and  the  dura  mater,  and  are  apt  to 
lie  destroyed,  or  at  least  cut.  when  removing  the  dura  mater;  notwithstanding 
this  they  can  he  traced  by  the  Amoves  in  the  hones  which  they  occupy.  The 
greater  part  of  the  anterior  branch  of  the  middle  and  the  terminal  part  of  the 
posterior  nieningeal  arteries  have  been  observed  when  removing  the  culvaria. 

The  middle  meningeal  artery. — The  largest  and  most  important  of  the 
meiiingcal  arteries  is  the  middle.  As  seen  when  dissecting  the  pterygo-max  :liary 
region,  both  this  and  the  small  meningeal  are  branches  of  the  internal  maxillary 
artery.  The  middle  meningeal  artery  runs  between  the  two  roots  of  the  auriculo- 
temporal  nerve  and  enter-  the  cranial  cavity  by  way  of  the  fora  men  spiimsum; 
it  occupies  a  groove  in  the  greater  wing  of  the  sphenoid  bone,  and  almost 
immediately  divides  into  two  branches,  the  anterior  and  the  posterior.  Small 
branches  of  the  middle  meningeal  artery  pierce  the  cranial  bones  and  anastomose 
with  the  vessels  of  the  scalp. 

The  iinfi-rinr  /n'l/nr/i  runs  through  a  groove  across  the  great  wing  of  the  sphe- 
noid, and  continues  into  another  groove  in  the  anterior  inferior  angle  of  the  parietal 
bone.  The  commencement  of  this  latter  groove  for  a  distance  of  one-fourth  to  one- 
half  of  an  inch  is  often  bridged  over  by  a  thin  plate  of  bone,  and  is  thus  converted 
into  a  canal.  The  vessel  continues  along  the  groove  near  the  anterior  border  of 
the  parietal  bone,  runs  almost  parallel  with  the  coronal  suture  to  within  a  short 
distance  of  the  superior  longitudinal  sinus,  and  gives  off  brandies  which  run 
upward  to  the  vertex  and  backward  toward  the  occipital  bone.  The  sinus 
ahe  parv;e  or  spheiio-parietal  venous  sinus  at  times  accompanies  the  artery- for  a 
part  of  its  course,  and  may  consequently  be  injured  in  fracture  or  during  the 
manipulations  of  the  surgeon. 

The  posterior  In-nm-li.  the  smaller  of  the  two,  crosses  the  squamous  portion  of 
the  temporal  bone  along  the  line  of  junction  of  the  squamons  with  the  petrous  por- 
tion, and  then  upon  the  posterior  inferior  angle  of  the  parietal  bone,  where  it 
divides  into  its  branches. 

Extra-dural  hemorrhage. — From  the  relation  which  the  anterior  branch 
of  the  middle  meningeal  artery  holds  to  the  anterior  inferior  angle  of  the 
parietal  bone,  it  follows  that  fracture  of  this  part  of  the  skull  is  apt  to  result 


598  SUR<:H'.\L  AX  ATOMY. 

in  hemorrhage,  which  would  he  located  between  the  hone  and  the  dura  mater. 
The  vessel  may  lie  injured  either  hy  sharp  bony  spieula  or  by  (lie  sudden 
alteration  in  shape  to  which  the  skull  is  subjected  in  cases  of  severe  head  injury. 
It  has  already  heen  noted  that  the  dura  mater  is  loosely  attached  to  the  vault 
of  the  cranium;  this  accounts  for  the  six.e  of  the  large  extra-dnral  blood-clots 
oreasionally  seen.  From  the  relation  of  this  branch  to  the  motor  area  of  the 
brain  it  can  readily  be  understood  why  the  symptoms  eonse,|uenf  upon  the 
pressure  of  an  extra-dnral  clot  are  largely,  if  not  altogether,  motor.  The-e 
eases  constitute  an  especially  favorable  class  for  trephining,  which  should  be  done 
as  soon  as  the  diagnosis  is  made,  or  as  early  as  possible.  If  upon  the  removal 
of  the  clot  the  bleeding  has  not  ceased,  the  vessel  should  be  tied.  This  may 
••ssitate  enlarging  the  original  trephine  opening  in  order  to  expose  the 
bleeding  points.  The  author  lias  found  it  necessary  to  tie  both  the  anterior  and 
the  posterior  branch.  It  occasionally  happens  that  the  injury  to  the  middle 
meningeal  artery  occurs  on  the  opposite  side  to  that  upon  which  the  external 
!<  sioii  exists. 

Point  for  trephining. — The  point  of  election  for  applying  the  trephine  in  a 
suspected  case  of  extra-dural  hemorrhage,  meningeal  in  origin,  is  at  a  point  one 
and  one-half  inches  behind  and  one  inch  above  the  external  angular  process  of  the 
frontal  bone.  When  a  simple  or  a  compound  depressed  fracture  is  associated  with 
the  hemorrhage,  the  trephine  should  be  applied  near  the  fracture.  To  reach  the 
posterior  branch  the  trephine  should  be  applied  immediately  below  the  parietal 
eminence,  and  on  the  same  horizontal  level  as  in  the  preceding  operation.  The 
opening  can  subsequently  be  enlarged  in  a  downward  or  backward  direction  and 
the  vessel  thus  brought  into  view. 

Branches  of  the  middle  meningeal  artery. — The  middle  meningeal  artery 
gives  off  branches  within  the  cranial  cavity  to  the  (lasserian  ganglion:  a  petrosal 
branch,  which  enters  the  hiatus  Fallopii  to  supply  the  facial  nerve  and  anasto- 
moses with  the  stylo-mastoid  branch  of  the  posterior  auricular  artery;  a  lacrymal 
branch  which  enters  the  orbit  by  way  of  the  sphenoid  fissure,  or  by  a  separate 
canal  in  the  greater  wing  of  the  sphenoid  bone,  and  anastomoses  with  the  oph- 
thalmic artery;  a  branch  to  the  tensor  tympani  muscle;  and  branches  which 
have  the  cranial  cavity  through  foramina  in  the  great  wing  of  the  sphenoid 
bone  to  anastomose  in  the  temporal  fossa  with  the  deep  temporal  arteries.  It  is 
accompanied  by  two  veins  which  empty  into  the  internal  maxillary  vein. 

The  anterior  meningeal  arteries  are  branches  of  the  ethmoid  arteries ;  they 
supply  the  dura  mater  of  the  anterior  cranial  fossa  in  the  region  of  the  median 
line.  One  of  the  arteria  receptaculii,  derived  from  the  cavernous  portion  of  the 
internal  carotid  artery,  supplies  the  dura  mater  of  the  middle  cranial  fossa.  It 


7V//-:   MEMBRANES   AND    IV-»7-.7>'    OF   THE  J!1!AL\. 

anastomoses  with  the  middle  meningeal  artery,  an<l  it  also  receives  tlie  name 
of  anterior  meningeal.  The  dura  mater  of  the  middle  eranial  fossa  is  Mipplied 
chielly  liy  the  small  meningeal  m-ln'i/.  a  branch  of  the  intLTiial  maxillary,  \vhieh 
enters  the  cranial  cavity  by  way  of  the  foramen  ovale,  and  one  or  two  branches 
from  the  ascending  pharyngeal  artery,  which  enter  the  cranial  cavity  through 
the  middle  lacerated  foramen. 

The  posterior  meningeal  arteries  are  the  cranial  brandies  of  the  ascending 
pharyngeal.  the  occipital,  and  the  vertebral  arteries;  I  hose  arising  from  the 
ascending  pharyngeal  and  the  occipital  artery  enter  the  cranial  cavity  by  way 
of  the  posterior  lacerated  or  jugular  foramen,  and  those  from  the  vertebral  artery 
by  way  of  the  occipital  foramen  (foramen  magnum);  they  supply  the  dura  mater 
of  the  occijiital  or  posterior  cranial  fossa. 

The  ascending  pharyngeal  artery  also  sends  a  meningeal  branch  through 
the  middle  lacerated  foramen,  and  an  occasional  one  through  the  anterior  condy- 
loid  foramen. 

The  meningeal  veins,  with  the  exception  of  those  accompanying  the* middle 
meningeal  artery,  empty  into  the  siiniM  -. 


INDEX. 


In  this  I 


ludi-x  tlif  ivfViviHv-  in  heavy=face  type  :irr  to  the  pages  eontainina  ]»lates  illtistrnling  the 

subjeet  named.     HelVivm.-^  m   ix-^ular  type  art-  tu  tb<-  trxt. 


Abdomen,    viscera    of,     relation, 

363 

Abducent  nerve,  592 
Abductor    indicis   in.,  '211,  159, 

173,  206 
action,  212 
blood  supply,  212 
insertion,  211 
nerve  supply.  212 
origin,  211 
relations,  212 

minimi  digiti  in.  (hand),  172, 
140,  141, 
159,  173, 
206 

action,  179 
blood   supply, 

179 

insertion,  172 
nerve   supply, 

179 

origin,  172 
relations,  179 
pollicis  m.  (hand),  171,  140, 

141,  159 
action,  171 
blood  supply,  171 
insertion,  171 
nerve  supply,  171 
origin,  171 
relations,  171 
Abscess  beneath  temporal  fascia, 

484 
cold,  :;:.<; 

lumbar,  356,  409 
mammary,  58 
of  axilla,  27,  79,  95 
of  carpal  bursa,  158 
of  face,  490 
of  band,  37 

incision  for,  37 
of  lacrymal  sac,  508 
of  palmar  bursa,  158 

fascia,  deep,  158 
of  pectoral  region.  68 
of  ptervgo-maxillary  region, 

556 

of  scalp,  481 
of  shoulder  joint,  379 
of  sulxleltoid  bursa,  379 
of  vertebrae.  356 

cervical.  356 

dorsal,  356 

lumbar,  356 


Abscess  of  wrist,  :','! 
parotid,  521 

incision  for,  522 
psoas.  356 

retro-pbaryngeal.  356 
Arrrssorius  ad    ilio-costalem  in., 
399,  396,  397.      J7</c  Ac 

iv-sorius  M. 

muscle.  399 

action,    loo 
insertion,  399 
nerve  supply,  400 
origin.  399  * 
relations.  :!!!!! 
Arres-.on     ligament    of  shoulder, 

223 

Acime  of  mammary  gland,  55 
Acromial  angle,  351,  362,  43 

branch    of    acromio-thoracic 

•A..  1-.  83 
anastomosis,  85 
rete,  85 
Acromio-chu  ieular     joint,      218, 

219.       ]'iii(    Scapulo-cla- 

vicular  Joint,  221 
ligaments,  221 

inferior,  221,  218 
superior,  221,  219 
Acromion  process,  is.  43 
epiphysis.   1- 

u'uunitcd,  266 
fracture,  18,  270 
Acromio-thoracic  a.,  85,  70,  71, 

76 

acromiul  branch,  48 
branches,  85 
descending  branch,  48 
thoracic  branch,  48 
Adductor   oblique  in.  of  thumb, 

171 
pollicis  m.,  172,  140,   141, 

159,  206 
action,   172 
blood  supply,  172 
insertion,  172 
nerve  supply,  172 
origin,  172 
relations,  172 
Adhesions   of   mammary  gland, 

58 

Adipose  tissue  of  axilla,  95 
Alar  thoracic  a.,  85.  76 
Alveolar  a.,  548,  542 
Amazia,  63 

601 


Ampulla;  of  mammary  gland,  54, 

55 

Amputation,    general    considera- 
tions, 25!) 

methods  used  in,  280 
circular,  2-n 

modified.  280 
flap,  2S1 
Lister's.  282 
oval.  2*3 
Spruce's.   2-2 

Teale'sSSl 

of  arm.  293 

structures  involved,  293 
of  elbow,  288 

stiuetures  involved.  2-- 
of  forearm.  2-7 

flexor   carpi    uhlans    in. 

in.  131 

structures  involved.   2-7 
of  phalanges.  2-3 

structures  involved,   2*:! 
of  shoulder-joint.  •".*'.', 

structures  involved,  293 
of  thumb,  37.  284 

structures  involved.    2-1 
of  upper  extremity,  279 

general      considerations, 

27!  I 

Anastomosis  of  acromial  with  su- 
pra-scapular  and   po-- 
terior  circumtlex  a.,  -is 
branch    of  acromio-tho- 
racic a.,  85 

of  anastomotica  magna  a.,  114 
of  angular  a.,  508 
of  anterior  circumflex  a.,  85, 

88 

temporal  a..  470 
nlnar  recurrent  a.,  147 
of  arm,  324 
of    arteries   around    scapula, 

84,  385 
of  circumflex  a.,  85 

anterior,  85,  89 
posterior.  85,  86 
of  coronary  a.,  507 

inferior,  507 
superior,   507 
of  dorsal  digital  a.,  211 
of  tlorsalis  indicis  a.,  211 

scapula;  a..  86,  3s4,  385 
of  facial  a.,  512 

transverse,  508 


INDEX. 


Anastomosis  of  frontal  a.,  170 

ill'  humeral  liranch  of  acromio- 

thoracic  a.,  s,"> 
of  inferior  coronary  a..  507 

labial  a..  5117 

or  long  thoracic  a.,  85 

prol'unda  ;i.,  114 
of  infra-orbital  a..  5  In 
of  internal  mammary  a..  s."> 
of interosscous  a.,  palmar,  180 
posterior.  208 

recurrent  a.,  -Mil) 
of  lateralis  nasi  a.,  .",0- 
of  mammary  lymphatics,  57 
of  mental  a..  540 
of  occipital  a.,  470 
of  palmar  interosseous  a..  1-0 
of  perforating  a.,   IbO,   173, 

177 
superior,     of    hand, 

180 
of  posterior  auricular  a.,  470 

circumllex  a..  *5.  si; 

interosseous  a.,  2os 

-eapular  a.,  -li.  384,  385 

temporal  a.,   170 

ulnar  recurrent  a.,  147 
of  princeps  ccrvicis  a..  402 
of  profunda  ccrvicis  a.,  403 
of   radial    recurrent    a.,  144, 

180 

of  recurrent  carpal    a.,  180 
of  scapular  a..  s(j 

posterior,  86,  ::-'!,  385 

of  subscapular  a.,  385 
of  superior  coronary  a  ,  507 
perforating   a.   of  hand, 

180 

prot'unda  a..  113,  192 
thoracic  a  .  S5 
ulnar  recurrent  a.,  147 
of  supra-orbital  a.,  4liil 
of  supra-scapular  a.,  sr>,  384, 

385 

of  transverse  facial  a.,  508 
Anastomotica  magnaa.,  114, 110, 
111,    115,  118, 
128.  145 
anastomosis,  1 14 
branches,  114 

Anatomic    neck     of    humerus, 

fracture,  273 

displacement 

in,  273 

structures      in- 
volved, '37:5 

of  scapula,  fracture,  270 
snuff-box,  32 

branches  of  radial  a.  in, 

32 

contents,  32 

incision    to    expose    ra- 
dial a.  in,  337 
radial  a.  in,  339 
Anatomy,  long  bones,  256 

structural,  of  arteries,  298 
Ancouens  m.,  202, 184, 194,  200 
action,  202 
blood  supply.  202 
insertion,  202 
nerve  supply,  202 
origin,  202 
relations,  202 


Ariel's  method  of  treating   ancii- 

rysin,  2!  17 

Anesthesia,  temporal  a.  in,    170 
Anenrvsm.  artci  io-venous.  si 
ciisoid,  470,  463 
general  considerations.  -Jill 
method  of   treating,   Auel's, 

297 

Antyllns'.  2!»7,  295 
Brasdor  s.  21)7,  295 
coagulating      mate- 
rial. -»is 

foreign  body,  2!'s 
ga  1  v  a  no-puncture, 
~   29s 

Hunter's.  21)7.  295 
manipulation,  2!)8 
pressure.  2117 
War  drop's.    2!i7. 

295 

treatment  of.  294 
varicose.  :!01).  295 
\neurvsmal  varix.  30S,  295 
Angle,  acromial,  351,  362,  43 
at  elbow,  17,  21 
of  sca]>ula.  inferior.  3li2 
Angular  a.,   502,508.  472,  477, 

504 

anastomosis.  508 
rein,  509 
Ankvlosis,  false,  215 

of  elbow  after  excision.  2(i:! 
Annular  ligament  of  wrist,  anter- 
ior, 121).    157. 

2::o.       159, 

173 
compartments, 

157,  167 
relations,  157 
posterior.    12!),    196, 

194.  206 
compartments. 

1(17 
Anomalies  of  inammarv    glands. 

63 

Antecubital  fossa,  38 
Anthelix.       J'/Wc  Antihelix. 
Antihelix,  524.  525 
fossa,  524.    525 
Antitragicus  in.,  529,  527 
Antitragus,  524,  525 
Antvllus'     method     of     treating 

aneurysm,  2!)~.  295 
Aponeurosis,  bicipital,   110,  110, 
115,    128,      131,     135, 
140,  141 
of  latissimus  dorsi  m..  373. 

396 
of  occipito-frontalis  m.,  479, 

463,  491 
snbscapular,  387 
vertebral,  394 
Appendages  of  eye,  512 
Arachnoid   membrane   of   brain, 

573 

of  cord,  431,  429 
Arch,  anterior  carpal,  173 
bony,  of  shoulder.  1  -i 
carpal,  anterior.  173 

hemorrhage  from.  180 
posterior,  210,  194 

branches,  210 
coraco-acromial,  222 


Arch,     deep    palmar.    171),    145, 

173,  177 
branches,   1-u 
course.    ]s(l 
line.      122,       176, 

300 

relations,  180 
wounds.  ls() 
palmar,  dec]).  17!).  145,  173, 

177 

branches,  Isn 
course.   ISO 
line.      122,       176. 

300 

relation^.  1-0 
wounds,  180 
superficial,      147,      1(11. 

145,  159,  177 
branches.  161 
course,   lo'l 
formation,  161 
line,      122,      176, 

300 

relations.  161 
posterior  carpal.  210,  194 

branches,  210 
prccarpal,  148 
superficial    palmar.   147.  101, 

145,  159.  177 
branches,  llil 
course,    llil 
formation.  161 
line.       122,      176, 

300 

relations,  1(!1 
supra-orbital.  457 
/ygomatic,  460 

Areas  of  spinal  cord,  motor,  445 
rellex,  445 
sensory,  445 

Areola  of  nipple,  54,  55 
Areolar  tissue  of  axilla,  95 
of  eyelids.  516 
of  scalp,  4-o 
Arm,  amputation  of,  293 

structures  involved,  293 
arteries,  superficial,  103 
back  of,  dissection  of,  1-s 
fascia,  deep.  Iss 
muscles  of,  185 
collateral     circulation,     dia- 
gram, 324 

comparative  lengths  of,  18 
edema,  81 
fascia,  deep.  100 
front  of,  96 

cutaneous  nerves,  96 
dissection.  96 
fascia,  deep,  107 
lymphatic   glands.    104, 

105 

vessels,   104,  105 
muscles,  104 
veins,  superficial,  100 
intermnscnlar     septa,      107, 

110 

landmarks,  21,  24,  25 
measurements,  47 
movements  of,  in  affections 

of  the  breast,  58 
nerves,  120 

osteo-fascial     compartments. 
108 


INDEX. 


003 


Ami,   osteo-Iasrial   ciilll|iill-|  lllcllts. 

(•(intents,    in* 
section    of,    transverse,    290, 

291 

superficial  arteries,   UK! 
fascia  of  front,  !)(> 
veins.  103 

\as:i  alierrantia,  114 
Arm-pit,  the,  71.      I'/ili  Axilla. 
Arnold's  ganglion.  .">.Vi 
Aiteria  se|itnm  narinm.  .",(17 
Arteria-  receptacnli.  .">:):; 
Arterial     blood    ill     lacial    vein, 

511 
Arteries,      anastomoses,     around 

scapula.  84,  385 
anatomy,  •.!!)-< 
divided  in  excision  ol'  breast, 

libation,  gangrene  following, 

304 
general      considerations, 

303 
hemorrhage       followiii", 

304 

of  back,  367 
of  ear,  529 
of    face,     4(>0,     472,     477, 

504 

of  forearm,  145 
of  hand,  145,  177 
lines.  35 
of  back,  206 
of  palm,  176 
of  scalp,  152,  4(i!l,  472,  477, 

504 
of  septum  of  nose.  507.  472, 

477.  504 
hemorrhage      from, 

507 

of  spinal  cord,  44  1 
of  upper  extremity,  ligation, 

394 

lines,  122,  300 
sheath.  298 

.superficial,  of  arm,  103 
Artei  io-venons  aiieurysin,  81 
Artery,  acromial   branch  of  acro- 
mio-thoraeic, 
48,  85 

anastomosis.  85 
acromio-thoracic,  85,  70,  71, 

76 

acromial  branch,  48,  85 
branches,  85 
descending    branch,    48, 

85 
thoracic  branch,  48,  85 

anastomosis.   -5 
alar  thoracic,  85.  76 
alveolar,  548,  542 
anastomotica     magna,     114, 
110,    111,    115, 
118,  128,  145 
anastomosis.  114 
branches,  114 
angular.  502,  508,  472,  477, 

504 

anastomosis,  508 
anterior  auricular,  472,  477, 

484,  504 

carpal,  radial,  144,  145, 
135.  173,  177 


Artery,     anterior    carpal,     ulnar. 
1  K  135, 

340,  141, 
145,  173, 
177 

anastomosis,  1  H 
circumflex,   S9,   76,  77, 

111,  118 
aiia.-tomosis.  -II 
branches.  -9 
ill  excision  of  shoul- 
der-joint, -li 
deep  temporal,  547,  542, 

546,  550 
dental,  540 
intercostal  o  f  internal 

mammary.   I* 
interosseous,    117.  140, 
141,  145,  177,  203 
mcningcai.  5ii- 
spinal,  441,  429,  433 
superior      dental,      548, 

549 
temporal.    470.    467, 

472,  477,  504 
anastomosis,  470 
ulnar     recurrent,     147, 
111,       140, 
141,  145 
anastomosis,  1  17 
articular  branch  of  posterior 

interosseous,  208 
auricular,  anterior,  470,  472, 

477,484,  504 
anastomosis,  470 
deep,   547,   546 
posterior.  470.  467,  472, 
477,    484,    504, 
542 

anastomosis,  470 
axillary,  81,  62,  72,  76,  77, 

111 
branches  of  iirst  portion, 

82 
of    second     portion, 

85 

of  third  ]Hirtion.   M! 
course,  27,  81 
digital    compression,    82 
divisions,  82 
first  portion,  82 

branches,  82 
incision  for  libation.  301 
ligation,  8:>,  :',OI 

collateral  c  i  r  e  u  1  a- 

tioii  after,  306 
line  for,  45 
operation   to    expose, 

316,  317 
pressure  upon, "81 
relations,     82,    89,    305, 

316 
second  portion,  85 

branches,  85 
third  portion,  85 

branches,  86 
bicipital   branch  of  anterior 

circumflex,  89 

brachial,    108,     110,     111. 
115,  118,  128,  131, 
135,  140.  141,  145 
branches.  113,  111 
course,  28 


Arterv,  bracial,  incision  for  liga- 

tiou,  301 
ligation,  307 

collateral       circula- 
tion alter.  3o>.  :;i  111 
structures  involved, 

307 

line,  108,  307,  122,  300 
operation       to       expose, 

316,  317,  319 
relations,  108,  307,  316, 

317 

at  elbow.  328,  329 
vena;  comites,  1  13 
buccal,  548,   542,  546,  559 
carotid,    common,    line    for, 

487 

external,  542.  546,550 
internal,  5!)3,  579 

course.  593 

carpal,  anterior,   radial.   144, 
135,       145, 
173,  177 
anastomosis, 

148 
ulnar,     148.      135, 

140,  141,    145, 
173,  177 

posterior,     radial,     2*1, 
145,    177,   200. 
206 
ulnar.     211.      140, 

141,  177,    200, 
206 

recurrent.      180,       145. 

173,  177 
anastomosis.  1-0 
course,   180 
circumflex,  184,  185 

anterior,     89,     76,     77, 

111,  118 
anastomosis.    -'."..    -II 
branches,  89 
in  excision  of  shoul- 
der-joint. 89 
posterior,  85,  111,  184, 

185 

anastomosis,    85,   86 
incision  lor,  40 
ligation.  306 

structures      in- 
volved, 306 
operation  to  expose, 

341 
collateral  digital,  162,   140, 

159.  173,  177 
line.  176 
common  carotid.  487 

line,  487 
interosseous,    147.   140, 

141,  145,  203 
coronary,  inferior,  of  lip,  5o7, 
472,       477, 
504 

anastomosis,  507 
course,  507 
superior,  of  lip,  507.472, 

477,  504 
anastomosis,  507 
deep  auricular,  547,  546 
temporal,  anterior,  542 
posterior,  547,  542, 
546 


604 


IXDI-:\. 


\ilery,  dental,  anterior,  546 

superior.  .M-i.  559 
inferior,  517.  542,  546, 

550,  559 

middle  superior,  559 
|pi)sterior,  it-lS,  546 
desci-ndinf:    branch    of   acro- 

mio-thoracic.    H 
palatine.  54*.  546 
digital,   of  hand,    161,   140, 
141,    145,    156, 
159,    173,     177 
collateral.  102,  140, 
159,       173, 
177 

line,  176 
dorsal,  211 

anastomosis,  211 
Hue,  176 

of    bifurcation, 

37 

relations.  Hi'J 
dorsal      interosseous,       145. 

177,  206 
dor-alis    indicia.    211,     145, 

177,  200,  206 
anastomosis,  211 
pollicis,  311,  145,  177, 

200,  206 

scapula;,     86,     384.    76, 
77,     84,    111, 
185,  343,  385 
anastomosis,  8(i,  .'I-  1, 

385 
external  earotid.    542,   546, 

550 
mammary,  deep,  58,   85 

superficial,  58 
ptervsioid,  548,  546 
facial.  472,  477,  484,  485, 

504 

anastomosis,  512 
brandies,  5(17 
course.  502 
line,  487 
relations,  502 
transverse,     472,     477. 

484,  504,  542 
anastomosis.  508 
frontal,  470,  467,  472,  477, 

484,  504 
anastomosis.  470 
Rinjiival,  546,   559 
luimeral  branch  of  acromio- 

thoracic,  85 
anastomosis,  85 
incisive,  547,  546 
inferior  coronary,  of  lip,  507. 
472,477,504 
anastomosis,  507 
course,   507 
dental,  547,   542,    546, 

550,  559 
labial,   507,    472,   477, 

504 

anastomosis,  507 
profnnda,   of  arm,    113, 
110,     111, 
115,     118, 
128,  145 
anastomosis,  114 
thoracic,  85 

anastomosis,  85 


Artery,  infra-orbital,  54o,  5 4.-. 
484,  542,  546,  550, 
559 

anastomosis.  5  HI 
intercostal,  anterior,  of  inter- 
nal mammary,  48 
internal  carotid.   5!i:!,  579 

course,  593 
mammary.  --5 

branches,  48 
maxillary,    543,    544. 
484,   485,    542, 

546,  550,  559 
branches,  547 
divisions.  547 

ptervgoid,  548,  546 
interosseons,     anterior,     147, 
140,  141,  145,  177, 
203 
common,  147.  140,  141, 

145,  203 
dorsal,  145,  177,  206 

lirst,  211 
of  hand,    37.  140,   141, 

159,  173 
line,   176 

palmar,  180,  145,  177 
anastomosis,    l-o 
course,  180 

posterior,  208, 140,  141, 
145,  194,  200, 
203 

anastomosis.  208 
branches,  208 
relation.  208 
recurrent,       208,      111, 

145, 200 
second,  210 
third.  210 
labial,     interior,     546,    472, 

477,  504,  546 
anastomosis,  507 
lateral  nasal.  477 

spinal,  44  1 
lateralis  nasi,  508 

anastomosis,  508 
long  thoracic,  53,  58,  76 
mammary,     deep     external, 

58.  S5 

external,  deep,  58,  85 
internal,  anastomosis,  >."> 
masseteric.    51-*,    485,   542, 

546 

mastoid.  403 
maxillary,  internal,  543,  514, 

547,  484,     485, 
542,    546,    550, 
559 

anastomosis,  85 
median,  of  forearm,  148,  140 

of  spinal  cord,  444 
meniugeal,  anterior,  598 

middle,  456,  547,  597. 
546,  550,  554, 
559,  573,  578, 
579 

branches.  597,  598 
wound,  598 
posterior,  599 
small,   547.    599,    546, 

550,  559 

mental,  540,  547,  484,  546, 
559 


Artery,  mental,  anastomosis.  510 
metacarpal.  211.  145,  200, 

206 

middle  meningeal.  456  550. 
5!I7:  546,  554, 
559,  573,  578, 
579 

branches,  5!I7,  5ii- 
\\onnd,  598 
superior  dental,  559 
temporal.     472,      504, 

477,  484 
mylo-hyoid,  547,   546,  550, 

559' 
nasal,  546 

lateral,  477 
naso-palatine,  5  I- 
mitrient,    of   humerus,   114, 

111 

occipital.     402,     470.     406, 
467,  472,  477.  504 
anastomosis.  470 
branches,  402 
ophthalmic,  579 
orbital,  472,  504,  546 
palatine,     descending,     54*, 

546 
palmar      interosseons,     1-n, 

145,  177 
anastomosis,  180 
course,  l-o 
pnlpehral,  546 
perforating   branches   of   in- 
ternal mammary, 
4s.  49 

of  interosseons  211 
of  hand,  180,  173,  177 
anastomosis.  Iso 
course,  180 

posterior  articular  branch  of 
the  superior  profnnda, 

113 

auricular.        170.      467, 
472,    477,    484, 
504,  542 
anastomosis.  470 
carpal,  radial.  211.  145, 

177,  200,  206 
ulnar,     211.      14O, 
141,    177,    200, 
206 
circumflex.      s.">.       111, 

184,  185 
anastomosis,  85.  S6 
incision,  40 
ligation.  30ii 

structures      irj- 

yolved,  306 
operation  to  expose. 

341 
deep  temporal,  547.  542, 

546 

dental,  548,  546 
interosseous,   208,    140, 
141,    145,    194, 
200,  203 
anastomosis.  208 
branches,  208 
relations,  208 
meninjieal.  599 
scapular,  384.  84,  385 
anastomosis.       384, 
86,  385 


L\DI:\. 


605 


Artery,         posterior         scapular, 

branches.  :;-  I 
relations,  384 
spinal,  444 
temporal,  47(1.  467,472, 

477.  504 
anastomosis.  470 
ulnar    recurrent,     147, 
111,  140, 141, 
200 

anastomosis,  117 
prineeps  cervieis.  4(1:2,  406 
anastomosis,    102 
branches,  402 
pollicis.   180.  140,  141, 
145,   159,    173, 
177 

branches,  180 
coinse.    1st) 
line,  176 
relalions,  1*0 
prolunda  eervicis,  403,  406 

anastomosis,  403 
inferior.  113,  111,  115, 

118.  128,  145 
anastomosis,  114 
superior.  113,  192,   110, 
111,    145,    184, 
194,  200 
anastomosis,  113, 

192 

branches,  113.  192 
relations,  192 
pterygoid,  542 

external,  548,  546 
internal,  548,  546 
pterygo-palatine,  548.  546 
radial,   143,  210,  110,   111, 
128,  131,  135,  140, 
141,  145,  159,  173, 
177,  194,   200,  206 
branches,  144,  210 

ill    anatomic    snuff- 
box, 32 
course,  31 
in    anatomic    snuff-box, 

339 
line  of  incision, 

337 

incision  for  lighting,  301 
ligation,  310 

collateral  circulation 

after.  :!11 
structures  involved, 

310 
line.  143,309,  122,  176, 

300 

pulsation,  31 
recurrent,   144,   131, 

145,  345,  347 
anastomosis,  144 
relations.  143,  210,  328, 

331,  333 
to  bicipital  aponeu- 

rosis,  119 
vena  comes,  128 
radialis    indicia,     180,    140, 
141,    145,    159, 
173,  177 
course,  180 
line,  176 

recurrent,  anterior  ulnar,  147, 
111,  140,  141,    145 


Artery,  recurrent,  anterior  ulnnr, 

anastomosis,  147 
carpal,    ISO,    145,   173. 

177 

anastomosis.  180 
course,  ISO 
interossecms,    20-\    111, 

145,  200 
posterioriilnar,  147,  111, 

140.  141,  200 
radial,   144,    131,    145, 

345,  347 
anastomosis,  11 1 
ulnar,  anterior,  147,  111, 
140,     141, 
145 
posterior,  147,  111, 

140,  141,  200 
scapular,   posterior,  384,  84, 

385 
anast  otnosis,  384, 

86,  385 
branches,  :!-'[ 
relations,  384 
small    meningeal,    547,    "'ii'i. 

550,  559 

spheno-palatine,  54.-%  546 
spinal,   127 

anterior,  444,  429,  433 
lateral,  444. 
]«>sterior,  444 
subclavian,    relations    of,    to 

axillary  ple.xns,  s!l 
snbinental,  546 
subscapnlar,  86,  76,  77,  84, 

111,  385 

anastomosis,  86,  385 
branches,  si; 
incision  for  ligation,  301 
ligation,  30!) 

structures  involved, 

306 

line,  86 

operation  to  expose,  343 
superficial,  of  arm,  103 
of  forearm,  129 
temporal,   484,   485, 
504,  542,  546,  550 
superficialis    vohe,    32,    144, 
131,    135,    145, 
159,  173,  177 
line,  176 

superior  corouarv.  of  lip,  507, 
472,       477, 
504 
an  as  tomosis. 

507 

profunda,  113,  192,  110, 
111,  145,  184, 
194,  200 

anastomosis,  113,192 
branches,  113,  192 
relations.  192 
thoracic,  82,  71,  76 
anastomosis,  85 
supra-orbital.  4(«),  467,  472, 

477,  484,  504 
anastomosis,  469 
supra-scapular.  384,  84,  385 
anastomosis,  85,  384, 

385 

relations.  384 
temporal,  470,  485 


Artery,  temporal,  anterior,  470, 
467,  472,  477, 
504 

anastomosis.  470 
deep.  547.  542,  546, 

550 

in  anesthesia,  470 
middle,  472,  477,  484, 

504 
posleiior.  170.  467,  477, 

504,  550 
anastomosis.  470 
deep,  547,542,  546 
superficial.    484,     485, 
504.  542,  546,  550 
thoracic    branch  of  acromio- 
thoracic,     48, 
85 

anastomosis.  S5 
inferior  or  long,  85 

anastomosis,  >."> 
superior,  82,  76 

anastomosis,  .-."> 
transverse  facial,   fills,    472, 
477,    484,    504, 
542 

anastomosis,  5(is 
tvmpanic,  547.  546,  550 
ulnar,  144,  111,  131,   135, 
140,  141,  145,   159, 
173,  177 
branches,  147 
course,  31 

guide  for  ligation,  134 
incision  for  ligation,  301 
ligation.  31 1 

collateral  circulation 

after,  311 
structures  involved, 

311 

line,  144,  122,176,300 

recurrent,  anterior,  147, 

111,      140, 

141,  145 

anastomosis, 

147 

posterior,  147,  111, 
140,      141, 
200 
anastoino>  i  s, 

147 

relations,  147.  328,  335 
vertebral,  408,  406 
Vidian,  548,  546 
Arthritis,  rheumatic,  215 

tubercular,  215 
Articular  a.,  of  posterior  interos- 

seons,  208 

posterior,  of  superior  pro- 
funda, 113 

branch  of  median  n.,  148 
of  posterior  iuterosseous 

n.,  209 

of  ulnar  n.,  151 
cartilage,  212 

Articulation,    acromio-clavicular, 
218,  219.      Vide  Scapnlo- 
clavicnlar. 
atlanto-axoid,  419 

central,   419,  421 
lateral,  419 
ligaments,  419 
movements,  420 


606 


IX  I)  EX. 


Articulation,  carpal.  '.':!- 

blood  supply,  242 
formation,  2.'!-^ 
ligaments,  23* 
movements.  2  12 
nerve  supply,  242 
carpo-mctaearpal,  231,   235 
tirst  set,  212 

blood  s  up  pi  v, 

-.'  I.") 

formation,  242 
ligaments,  2  12 
movements  245 
nerve  s  u  p  p  I  v, 

:.'  15 
second  set,  245 

lilood  sup  pi  v, 

2  15 

formation,  215 
ligaments,  245 
movements,  245 
nerve  supply, 

245 

elbow,  17,  224,  225 
amputation.  2" 
blood  supply,  22* 
bursa,  228 
excision,  262 
formation,  224 
ligaments,  227 
movements,  228 
nerve  supply,  228 
relations,  228 
syuovial  membrane,  228 
synovitis,  228 
inferior  radio-uluar,   17,  233, 

230,  231,  235 
blood  supply,  21!  1 
formation,  233 
ligaments,  233 
movements,  233 
nerve  supply,  2:!  1 
intercarpal,  238,  23i,  235 
intenuetacarpal,  245 
blood  supply,  246 
formation,  245 
ligaments,  245 
nerve  supply,  246 
iiiterphalangeal,  247 
blood  supply,  217 
ligaments,  217.  244 
movements.  2 17 
nerve  supply,  2 17 
position,  37 

.-ynovial  membrane,  247 
lateral  atlauto-axoicl,   1111 
medio-earpal.  211 

blood  supply,  212 
formation.  241 
ligaments,  241 
movements,  242 
nerve  supply,  242 
synovia!   membrane.  212 
metacarpo-phalaugeal,  246 
blood  supply,  246 
formation,  246 
ligaments,  24fi 
movements,  246 
nerve  supply,  246 
synovial  membrane,  246 
oecipito-atlantal,  423 
blood  supply,  424 
ligaments,  423 


Articulation,        oecipito-atlantal, 

movements.    I1.1:! 
nerve  supply,  424 
occipito-axoid,  ligaments,  420 
radio-carpal,  234,  231,  235, 

239 

blood  supply.  2:;- 
disarticulation,  284 
dislocation,  255 
excision.  263 
formation,  234 
ligaments.  231 
movements.  •_>:!-< 
nerve  sup|ily.  211* 
radio-ulnar,      inferior,      233, 

230,  231,  235 
blood  supply.  21!  I 
formation.  2:;:! 
ligaments.  233 
movements.  233 
nerve  supply,  234 
superior,  17,  233 

blood  supply,  233 
formation,  233 
ligaments,  233 
movements.  233 
nerve  supply,  233 
scapulo  clavicular.  221,  218, 

219 

blood  supply.  222 
formation,  221 
ligaments,  221 
movements,  222 
nerve  supply,  222 
relations,  222 
scapulo-bumeral,  218.     Tide 

Articulation,  Shoulder, 
shoulder,  222 
abscess,  379 
amputation.  293 
blood  supplv.  224 
bursa,  223 

dislocation.  24*,  249 
excision,  261 
formation,  222 
ligaments.  223 
movements,  224 
nerve  supply,  224 
relations,  221 
synovial   membrane,  223 
synovitis,  223 
stei  no-clavicular,  215,  214 
blood  supply,  216 
formation,  215 
ligaments,  216 
movements.  221 
nerve  supply,  221 
superior  radio-ulnar,  17.  233 
blood  supply,  233 
formation,  233 
ligaments,  233 
movements,  233 
nerve  supply,  233 
wrist.       Vide     Articulation, 

Kadio-carpal. 
Articulations,  212 
.     divisions,  215 

of  upper  extremity,  215 
Aspiration  of  pleural  sac,  351 
Asterion,  the,  455 
Athelia,  63 
Atlanto-axoid  joint.  419 

central,  419,  421 


Atlanto-axoid  joint,  lateral,  419 

movements.    Tin 
ligament.  415 

anterior,  419,  417 
capsular,  417 
posterior,    II!) 
superficial,  419 
svnovial  membrane.  417 
Atrophy  ofdcltoid  m  .  27.  251 .  379 
Attachments    of   dura   mater  of 

brain,  575 

of  muscles  of  scapula.  393 
Attolens  aurem  in.,  469,  491 
action.  4iili 
insertion,   liili 
nerve  supply.  4(19 
origin,  469 

Attraheus  aurem  in.,  469,  491 
action.    Kill 
insertion,  469 
nerve  supply,  469 
origin,   469 
Auditory  n.,  593 
Auricle,'  the,  524,  525 

landmarks.  524 
Auricular  a.,  anterior,  470.  472, 

477,  484,  504 
anastomosis.  470 
deep,  547,  546 
posterior,       470,      467, 
472,   477,    484, 
504,  542 
anastomosis,  470 
lymphatic-  gland.-,  566 

\c-ssels,  479 
nerve,  530 

anterior,  552 
great.   473 
posterior,  476 
region,  dissection.   521 
vein,  posterior,  509 
Auriculo-tempond    n.,    476,  552, 
473,  477,  484,  550, 
542,  554,  559 
divisions,  552 
Auscultation  of  chest,  352 
Axilla,  the,  27,  74,  76,  77 
abscess,  27.  79,  95 
contents,  80 
depth,  79 

dissection,  from  before  back- 
ward, 76 
from  below  upward,  95, 

77 

folds,  27,  24 
glands,  27 
landmarks,  27 
suspensory  ligament,  6-S 
walls,  79 
Axillary  a.,  81,  62,  72,  76,    77, 

111 

branches. first  portion.  -2 
second  portion,  85 
third  portion,  86 
course.  27.  M 
digital    compression,    82 
divisions,  >2 
first  portion,  s'2 

branches,  82 
incision  forligation,  301 
ligation,  82,  304 

collateral       circula- 
tion after,  306 


JM)EX. 


607 


Axillary  a.,  line.  45 

operation     to    expose, 

316.  317 
pressure   upon.  -1 
relations.     -•-'.     89,     305, 

316 
srrond  portion.  -"> 

l)ranehes,  85 
third  portion,  .-5 

bninehes,  86 
fascia,  li*,  71,  59 
diagram,  62 
lymphatic  Clauds,  92 

in  ea  r  i-  i  n  o  in  a  of 

breast,  92 

nerve  plexus,    89,    76,    87 
brandies.  00 
formation,  89 
incision    to    expose, 

301 

motor  points,  40 
pressure  upon.  .-!( 
relations,     t  o    axil- 
lary a.,  89 
to       subelaviau 

a.,  89 

stretching,  38,  311, 
:;i  I 

st  ruptures     i  11  - 

volved,  31-2 
vein,  HO,  62,  71,  76,  77 

pressure   upon.  *1 

relations,  316,  317 

wound,  57,   80 
vessels,  80 

sheatli.  -0 
wall,  anterior,  (i  1 

A.xo-appendicular  m.,  411 


B. 

Back,  arteries.  :!(i7 

cutaneous   nerves,    371,   369 
dissection,  307 
fascia,  deep,  371 
landmarks,  353 
muscles.  373,  396 

deep,  397 
nerves,  3(>7.  -109 
of  arm.  1*-* 
of  forearm,  195 
of  neck,  351 
of  shoulder,  351 
of  trunk,  351 
surface  markings,  353 
Ball  of  thumb,  32 
Base  of  skull,  fracture,  55(i 
Basilar  plexus.  578 
Basilic  v.,  104,  100,   110,   115. 

118,  128 
median.  103,  100,  110. 

128 

infusion  into,  104 
Bell,  external  respiratorv  n..  92 
Bell's  palsy,  534 
Bellv,  posterior,  of  omo-bvoid  in., 

378 

Biceps  m.,  27,  111.  24,  70,  76, 
77,    110,    115,    128, 
194,   200 
action.  119 
blood  supply,  119 


Biceps  m.,  grooves.  27 

head,  accessory.  119 
lonu.  115,  118 
short,  1111.115,118 
insertion,  119 
origin,  119 
relations,  119 
rupture,  130 
tendon,  110,  115,  118, 
128,  131,   135,  140, 
141 
Bicipital  aponeurosis,  119 

relation,  to  brachial  a., 

11!) 
branch  of  anterior  circumflex 

a.,  .-9 
nerve.  91 
fascia.  110,  115.  128,  131, 

135,  140,  141 
groove.  27 

I'.ivcnter  cer\  ids  in.,  402 
Blood-letting.  104 
Body  of  scapula,  fracture.  270 

pituitary,  579 
Bone,  cheek',    liill 

frontal,  sinuses,  455 
growth,  259 
marrow,  :.'59 
metacarpal,  169 
sesamoid,  of  thumb,  :!7 
Bones,  long,  anatomy.  •_'.">(; 

cancellons  tis.-ue.  '.'59 
nourishment,  259 
of  cranium,  -15:2 
of  upper  extremity,  develop- 
ment, 2(>6 

Brachial  a  .  10*,  110,  111,  115, 
118,  128,  131,  135, 
140,  141,  145 
branches,  113,  111 
course,  2* 

incision  for  ligatiou,  301 
ligation.  :vr, 

collateral       drenla 
lion     after,     308, 
309 
structures  involved, 

307 

line,  108,  307,  122,  300 
operation  toexposc,  316, 

317.  319 
relations.  108,  307,  316, 

317 

at  elbow,  328,  329 
vena1  comites.  113 
nerve  plexus,  7s,  76,  87 
branches.  9O 
formation.  89 
incision    to   expose, 

301 

motor  points,  40 
relations,  to  axillary 

a.,  89 
to      subdavian 

a..  89 
stretching,  38,  311, 

314 

structures      in- 
volved, 312 

Brachialis  aiiticus  m..  120,  115, 
118,  128,  131,  135,  140. 
141,  184,  194,  200,  345, 
347 


Brachialis  anticus  m..  action.  120 
blood  supply,  120 
insertion.  120 
nerve  supply,  120 
origin,   120 
relations,  120 
Brachio-radialia  m.,  197 
Brain,  arachnoid  membrane,  573 
compression,  572 
membranes,  5i>* 
preser\ation.  581 
removal.  .~>7<i 

vessels.   5<i* 

Brasdor's     method     of     treating 

aneiinsm,  297.  295 
Bieast,  'the.  53.  55.      Title  Mam- 
mary (ilaud. 

Breathing,  stertorous,  501 
Bregma,  4.">2 
Bronchi,  jiosition.  r!(i1 
Buccal  a.,  54*.  546,  559 

branch   of   eervico-facial  n., 

533 
of  facial  n..  473.    477. 

484 

glands.  502 
Ivmphatic  glands.  5d(i 
nerve.  552,  542,  550,  559 
portion    of    Stenson's    duct, 

523 
Buccinator  m.,    501.   485,  491. 

542,  550 
action,  502 
insertion.  501 
nerve  supply,  502 
origin,  501 
relations,  501 

Bucco-pharyngeal  fascia,  501 
Burdach,  column,  444 
Bursa,  carpal,  great,  157,  166 

abscess,  158 
of  mammary  gland,  54 
palmar,  157 

abscess.  158 
subaeromial,     inflammation, 

223 

subdeltoid,  379 
abscess.  :!79 
inflammation,  379 
Bursa1  of  elbow,  228 
of  oleeranon.  188 
of  shoulder-joint.  223 
of  upper  extremity,  28 


Canal,    central,    of   spinal    cord. 

43(i 

tumors  within,  449 
of  Huguier,  555 
osteo-librons,  of  hand,  1(!7 
Cancellous   tissue  of  long  bone, 

259 

Canprnm  oris,  490 
Cauthus,  external,  512 

internal.  512 
Cap  of  shoulder,  378 
Capsnlar     ligament    of    atlanto- 
axoid  joint,  419,  417, 
421 
of  carpal  joint,  238 


608 


INDEX. 


Capsular  ligament  ol'  carpo-incta- 
carpal  joint, 
first  set,  230, 
231 

second  sc-t.  2  1.") 
i.foccipito-atlantal  ioiiit, 

I-;:;,  417 
of    radio-carpal  joint. 

235 
lit'  shoulder  -  joint.    223, 

218 

of  vertebrae,  416.  413 
een  ical.  417 

Capsule  of  niaiiiniary  gland.  54 
Carcinoma,  course  of  metastasis,  07 
edema  of  ami,  -1 
ol' axillary  lymphatic  glands, 

92 

of  mammary  gland.  53.  57 
of  tubercles  nf  Montgomery. 

57 

Caries  ot'  vertebra'.  5 -Hi 
Carotid  a.,  546 

common,  line.  487 
external.  542,  550 
internal,  593.  579 

course,  "lit:! 

lobe  of  parotid  ".land.  .">•_'•> 
Carpal  arch,  anterior,  173 
hemorrhage,  180 
posterior,  310,  194 

branches,  210 

arterv.  anterior,  radial,  144. 
135,  145,  173, 
177 

uluar,  143,  135, 
140,  141, 
145,  173, 
177 

anastomosis,  148 
posterior,      radial,     211, 
145,    177,    200, 
206 

nl  liar,   211.   140, 
141,   177,    200, 
206 
recurrent,       180,       145, 

173,  177 
anastomosis.  IMIJ 
course,  180 
bursa,  157 

alisccss.  15~< 
great.    166 
joints,  23-i 

blood  supply,  242 
formation,  23-< 
ligaments,  238 
movements,  242 
nerve  supply,  242 
ligament,  dorsal.   231 
Carpo-metaenrpnl     joint,      231, 

235 
first  set,  2 12 

blood      snpplv. 

845 

formation,  242 
ligaments.  242 
movements,  215 
nerve     supplv, 

345 
second  set,  24,"> 

blood     snpplv, 
245 


Carpo-metacarpal    joint,    second 
set.        forma- 
tion, :2  15 
ligaments.  •'.  1"> 
movements,  :_'  l.~> 
nerve      snpplv. 

245 

ligaments,  anterior,  235 
Carpus,  centers  of  ossification,  269 
dcvelo]>ment,   269 
dislocation.  255 

st  inclines  involved,  2."if) 
excision,  203 
i'ructiire,  27s 

displacement,  278 
front  of,  31 
pisilorm  bone.  31 
synovia  I   membrane,  242 
Cartilage,  articular,  212 

interarticnlar,  210,  214 
of  pinna,  529 
tarsal,    \", .  510 
Carnncola  lachrymal  is,  512.  515. 

513 

Canda  C(|iiiiia,  435.  429,  433 
t'a\enioiis  sinus,  5S9.  579 

relation   of.  to  (Jasserian 

<;an<:lion.  o^ii 
Cavity,  glenoid,  219 
Cells,  gplenoidal,  578 
Centers  of  ossification  of  carpus. 

269 

of  clavicle.  2(i(i 
ot'  hnmcnis.  :.'(i'i 
of  metacarpal  IKHICS,  2(i!* 
of  ])halan^es.   2liU 
of  radius,  266 
of  scapula,  266 
of  ulna,  269 

Central  canal  of  spinal  cord,  4"6 
Cephalic  groove.  64 

vein,  27,  103.  59,  70,  71, 
76,  77,  100.  110, 
128 

median.  103,   100,    128 
C'erebellar  nerve  tract.   1  13 
Cerebral  fissures,  lines.  453 

vein,  superior.  573 
Cervical    enlargement  of   spinal 

cord.  428 

intertransversales  m..   IOT 
nerve,  eighth,  86 

posterior     division. 

410 
fifth,  87 

posterior      division, 

410 
first,    posterior    primary 

division,  409 
fourth.  87 

posterior      division, 

410 
second,  posterior  primary 

division.   H>!i 
seventh,  87 

posterior      division, 

410 
sixth,  87 

posterior      division, 

410 
third,  posterior  division, 

410 
nerves,  oriuin,  361 


Cervical  plexus,  posterior.  ol'Cru- 

veilhier,  4d!t 
vein,  deep,    Hi:!.    509 
\ertcbrie,  abscess,  ll.'iii 
diseases,  3."><; 
spine  of  seventh.  ::iil 

of  sixth.  3.'i(i 
( 'ervicalisasceiidens  m..  4(111,  396, 

397 

action.    Hid 
insertion,  400 
nerve  supjilv.  400 
origin,  400 
relations,  400 
CiTvico-hasilar    'ligament,      -I'.'O, 

421 

Check  ligament,  -123 
Cheek  bone.  460 
Chest,  auscultation.  3."i2 
]ierens.-ion.  '.',~fl 
supciticial  fascia,    I- 
Chordu    tvmpaui    n..    "I'M.    542. 

550,  559 

Chorda-  Willisii.  ."»:: 
Ciliary  in.,    of  orbicularis  jialpe- 

brarnm,  497 
Circular   method  of  amputation, 

280 

modified.  '.'-(I 
sinus.  .-,!:u.  578,  579 
Circulation,  collateral,  after  liga- 
tion  of  axillarv  a.. 
306 

brachial  a.,  ::os.  309 
radial  a  ,  311 
nlnar  a..  311 
of  arm,  diauram,  324 

of    clllONV.     Ill 

of  fingers,  diagram,  325 
of     forearm,      diagram, 

325 

of  hand,  diagram,  325 
Circnlns  tonsillaris,  562 
venosus.  llaller.  .">7 
Circumflex  a.,  184,  185 

anterior,     H9.     76,    77, 

111,  118 
anastomosis.  s,"»,  89 
branches.  .••!! 
in  excision  of  shoul- 
der-joint, 89 
posterior.  85.  Ill,  184, 

185 

anastomosis,  85,  t»ij 
incision,  40 
iigation,  306 

structures      in- 
volved, 300 
operation  to  expuse, 

341 
nerve,  90.  124,  380,   76,  77, 

87,  184,  185,  381 
branches.  90.  124 
cutaneous  branch,  97 
irritation,  314 
motor  points,  41 
operation  to  expose.  341 
stretching,  306 

structures  involved, 

306 

trauma,  124 
vein,  posterior,  341 
Cirsoid  aneurysm,  470,  463 


INDEX. 


609 


Classilication  of  joints,  215 
Clavicle,   K  62 

articulations.  1.- 
ccuters  ol'  ossilication,  266 
development,  206 
dislocation.  1-\  2H 

structures  involved,  248 
excision,  2(io 

structures  involved,  260 
fracture,  18,  269 

displacement,  270,  268 
structures  involved,  269 
sarcoma,  '.'lil 
Clavi-pectoral  fascia,  67 
Clavus.  5(11 
Clawed  hand,  277 
Coccyx,  361 

Collateral  circulation  after  ligation 
of  axillary  a.,  306 
hrachial  a.,  308,  309 
radial  a.,  .'!!  1 
ulnar  a.,  311 
digital   a.,    162,    140,    159, 

173,  177 
line,  176 

nerve,  162.  156,  159 
Colics'  fracture,  277,  276 

displacement,  277,  276 

structures  involved,  278 
Column  of  Burdach,  444 

ofTurck,  -t-13 
Columna,  nasal,   158 
Comedones.  521 
Comes  nervi  mediani,  147 
Commissure,  gray,  of  spinal  cord, 

436 

palpcbral,  f)12 
white,  of  spinal  cord,  436 
Common  carotid  a.,  line,  487 
interosseous    a..     147,    140, 

141,  145,  203 
ligament,   anterior,  of  verte- 
bra.-, 412,  413,  417 
posterior,    of    vertebrae 

412,  413 

Communications  of  facial  v.,  511 
Compartments  of  anterior  annular 

ligament,  157,  167 
osteo-l'ascial,  of  arm,  108 
posterior    annular   ligament, 

197 
Complexus  m.,   401,  373,  396, 

397 

action,  402 
blood  supply,  402 
insertion,  401 
nerve  supply,  402 
origin,  401 
relations,  401 
Compression,  digital,  of  axillary 

a.,  82 

of  brain,   572 
Compressor    nnrium    minor    m., 

491 

nasi  m.,  4!)3,  491 
action,  493 
insertion,  493 
nerve  supply,  493 
origin,  493 
Concha,  524,  525 
C'ondyles  of  humerus,  28 
fracture,  274 

displacement  in,  274 
39 


Condyles  of  humerus.   fractures, 

structures  imohcil,  274 
Congenital     variations    of    mam- 
mar/  gland,  li.'i 
Congestion  of  conjunctiva,  515 

of  seal)).    1711 

Conjunctiva.   515,  496,  517 
congestion,  515 
corneal  portion,  515 
palpcbral  ]>ortion,  515 
reflected  portion.  515 
sclerotic  portion,  515 
Conoid  ligament,  221,  218 
Contents  of  anatomic  snuff-box, 

32 

ofaxilla,  .-0 
of   infra-clavicular    triangle, 

deep,  73 

superlicial,  f>7,  70 
of  osteo-l'ascial  compartments 

of  arm, 108 
of  parotid  gland,  521 
of  ptervgo-maxillary  region, 

543 
of     spheno-maxillary    fossa. 

557 

of  suboccipital  triangle,  407 
of  triangle  at  elbow,  130 
of  zygomatic  fossa,  557 
Contraction    of    fingers,     Dupuy- 

tren's,  161 

Conns  medullaris,  428 
Cooper,   Sir  Astley,  ligament,  54 
Coraco-acromial  arch,  '!'!'! 

ligament,    27,    222,    115, 

118,  218,  219 

Coraco-brachialis    m.,     120,     65, 
70,     76,     77,     110, 
115,  118 
action,   120 
blood  supply,  120 
insertion,  120 
nerve  supply,  120 
origin,  120 
relations,  120 

Coraco-clavicular  ligament,  221 
Coraco-humeral    ligament,     223, 

218 
Corucoid   process,    18,    27(1,    43, 

115 

fracture,  270 
Cord,  spinal,  429,  439 

arachnoid,  431,  429 
areas,  motor,  445 
reflex,  445 
sensory,  445 
arteries,  444 
blood  supply,  427 
central  canal,  436 

tumors,  449 
commissure,  gray,  436 

white,  436 
disease,  446 
dissection,  428 
dura  mater,  428.  429 
enlargement,       cervical, 

428 

lumbar,  428 
fissures,  435 
in  fetus,  428 
injuries,  449 
lesions,  44(! 
median  a.,  444 


Cord,     spinal,     membranes,    42*, 

429 

motor    tract,     degenera- 
tion in,  450 
nerve  tracts,  443,  441 
pia  mater,  432.  429 
protection,  449 
sections,  437 
structure      of,       macro- 
scopic, 436 
veins,  445 
Corneal   portion    of  conjunctiva, 

515 

Coronal  suture,  452 
Coronary  a.,  inferior,  of  lip,  507, 
472,       477, 
504 

anastomosis,  507 
course,  507 

superior,  of  lip,  507, 
472,  477, 
504 

anastomosis,  507 
Coronoid   head  of  pronator  radii 

teres  m..  140,  141 
process  of  ulna,  278 
fracture,  278 

displacement, 

278 

structures     in- 
volved, 278 

Corrugatorsupercilii  m.,  498,496 
action,  498 
insertion,  498 
nerve  supply,  498 
origin,  498 

Costo-clavicular  ligament,  216 
Costo-coracoid  membrane,  68,  62, 

70 

Cranial  nerves,  579 
Crauio-vertebral  muscles,  41 

posterior,  407 
Cranium,  bones  of,  452 

landmarks,  451,  453 
Crest  of  ilium,  362 
Crista  Galli,  579 
Crucial  ligament  of  atlauto-axoid 

joint,  420,  421 

Cruveilhier,  cervical  plexus,  409 
Cuneiform  bone,  31 
Curvature  of  spine,  352 

annular.  355,  359 
lateral,  355,  358 
normal,  358,  359 
Cutaneous  branch,  dorsal,  of  ul- 
nar n.,   151,   196,   97, 
140,  141 
external,     of     musculo- 

spiral  n.,  97,  100 
inferior  external,  of  mus- 
culo-spiral  n.,  96 
of  muscnlo-spiral  n., 

188,  195 

internal,     of     muscnlo- 
spiral  n.,  103,  188,  77 
of  circumflex  n.,  97 
of  median  n.,  129 
of  ulnar  n.,  126,  151 
palmar,    of   median   n., 

148,  97 

of  radial  u.,  196,  97 
of    ulnar    n.,    151, 
97 


610 


INDEX. 


Cutaneous  branch,   superficial,  of 

muscnio  spiral  n.,  96 
nerve,  external,  126 

course,  38 

internal.     01,     06.     124, 
76,  77,  87,  97, 
100,  110,  128 
brandies,  124,  97 
course.  :iS 

lesser  im.Tii.-il,  103,  ]<s, 
195,  76.  77.  97,  110 
nerves,  anterior.  52 
lateral,  52 
of  arm,  97 
of  back.  :!71,  369 
of  forearm,  97 
of  front  of  arm,  96 
palmar,  153 
Cyst,  suhinammary,  ."is 


D. 

Darwin's  tubercle,  527 

Deep  palmar  arch,  179,  145,  173, 

177 

branches,  180 
course,  180 
line,  122, 176,300 
relations,  180 
•wounds.  180 
Degeneration    in    motor   tract  of 

spinal  cord,  450 
Deltoid  m.,  27,  378,  65,  70,  71, 

76,     77,    110,    115,    I 
184,  341,  373 
action,  379 
atrophy,  27,  251,  370 
blood  supply,  379 
insertion,  37* 
nerve  supply,  379 
origin,   378 
relations,  378 
tubercle,  18 

Delto-peetoral  sulcus.  64 
Density  of  temporal  fascia,  482 
Dental  a.,  anterior,  546 

superior,  548.  559 
inferior,  547,  542,  546, 

550,  559 

middle  superior,  559 
posterior,  548,  546 
nerve,  anterior  superior,  561, 

559 
inferior,  555,  542,  550, 

559 
middle     superior,      558, 

559 
posterior   superior,    558, 

542,  559 
Depressor  aku  nasi  m.,  494 

action,  494 
insertion,  494 
nerve;      supply, 

494 

origin,   494 

anguli  oris  m.,  500,  491 
action,  500 
insertion,  500 
nerve     supply, 

500 

origin,  500 
relations,  500 


Depressor  labii  inferioris  m.,  500, 

491 

action.    50(1 
insertion,  500 
nerve      supply, 

600 

origin,  500 
relations.  5011 
Descending   branch    of    aeroiuio- 

thoracic  a.,  48 
palatine  a..  518,  546 
Development    of   bones  of   upper 

extremity,  266 
of  carpal  bones,  269 
of  clavicle,    26(i 
of  humerus.  2(>6 
of  mctacarpa!  bones,  269 
of  phalanges.   200 
of  radius.  -;i;(i 
of  scapula,    20(i 
of  ulna,  2li!) 

Diagnosisof  lobar  pneumonia.  3.V" 
Diagram  of  axillary  fascia,  62 
of   collateral     circulation   of 

arm,  324 
of  lingers,  325 
of  forearm,  325 
of  pectoral  fascia,  62 
Diaphragm  of  pituitary  fossa,  581 
Diaphragma  selhc,  581 
Digastric  fossa,  455 

nerve,  533 
Digital  a.,  collateral,    162.  140, 

159,  173,  177 
line,  176 
dorsal,  211 

anastomosis,  211 
of  hand,  161,  140,  141, 
145,    156,    159, 
173,  177 
line,  176 

of    bifurcation, 

37 

relations.  102 

compression  of  axillary  a.,  82 
nerve,   collateral,    103    156, 

159 

from  median  n.,  167 
from  radial  u.,  97 
from  ulnar  n.,  162,  159 
I'acinian  bodies,  167 
relations.  1(!7 
Dilator  uaris  m.,  403 

action,   403 
insertion.  403 
nerve  supply,  493 
origin,   403' 
narium  in.,  anterior.  491 

posterior.  491 

Dimple  behind  elbow,  28,  25 
Diploe,  463 
Diploic  v. ,  568,  569 
Disarticulation      of     metacarpal 

bones,  284 
structures  involved, 

284 
of  radio-carpal  joint,  284 

structures  involved. 

287 
Discs,    intervertebral,    412,   413, 

425 

Diseases  involving  facial  v.,  511 
of  spinal  cord,  446 


Di.-location  at  elbow,  252 

at  radio-carpal  joint,  255 

of  biceps  lendoll,  27 

of  carpus.  255 

of  clavicle.  -il> 

of    humerus,    18,    248,    29, 

249 

snbelavicular.  251 
snhcoiacoid,  251 
subglenoid,  27,  248 
snbspiiions,  251 
of  metacarpal  bones,  255 
of  phalanges,  256 
of  radius.  -25  I 

and  ulna,  252 
of  scapula,  222 
of  ulna,  255 
of  vertebra',  424 
subelavieular,    of    humerus, 

251 

subcoracoid,  251 
stibglcnoid,  27,  248 
snbspinous,  251 

Dislocations,    general   considera- 
tion, 247 
Displacement  in  fracture.  Colics'. 

of  radius.  277,   276 
of  carpus,  278 
of  clavicle,  270,  268 
of  condvles  of  linmerns, 

274 
of   coronoid    process  of 

ulna,  278 
of    humerns,     condvles. 

274 

epiphysis,  273 
intcrcondyloid,  274 
neck,  anatomic.  '-'7:1 
surgical,      273, 

272 

shaft,  273 

su  pi  a-condyloid,  274 
tuberositv,     greater, 

273 
of     metacarpal      bones, 

278 
of    neck,     anatomic,    of 

humerus,  273 
surgical.       of      Ini- 

mern~.  27:1.  272 
of  olecranon  process  of 

ulna,  278 
of  phalanges,  270 
of  radius,  277,  276 

and  ulna,  278 
of  shaft  of  humerus,  276 
of  ulna.  27s 
snpra-condyloid,   of  hu- 

merns.  27  1 
Dissection  of  arm.  back,  188 

front,  06 

of  auricular  region,  524 
of  axilla,   from   before  back- 
ward, 74,  76 
from  below  upward,  95, 

76 
of  back,  367 

incision,  365 
of  arm,  188 
of  forearm.  105 
of  hand,  209 

of   deep  infra-clavicular  tri- 
angle, 73 


L\DJ-:X. 


(ill 


Dissection  of  dura  mater.  575 
of  liice.  4*9 

incision,  461,  487 
of  forearm,  liaek,  195 

front,  125 
of  front  of  arm,  ill! 
of  forearm,  125 
of  hand,  152 
of  baud,  back,  209 

front,  152 
of   infra-clavicular   triangle, 

deep,  73 
sllpel  tielal,  (i7 
of  niemlirancs  of  brain,  571 

of  spinal  cord,  428 
of  neck,  incision,  487 
of  palm  of  hand,  152 
of  pectoral  region,  48 
of  pterygo-maxillary  region, 

5  411 

of  scalp,  4(!5 
of  spinal  cord,  428 
of  superficial  infra-clavicular 

triangle,  67 

of  temporal  region,  489,  485 
of  upper  extremity.  47 
Dorsal  ligament  of   carpal  joint, 

238,  241 
of   carpo  m  ct  a  carpal 

joint,  212 
of  internietacarp.il  joints, 

245 
vertebra;,  abscess,  1556 

caries,  356 
Dn'salis    iudicis    a.,     211,    145, 

177,  200,  206 
anastomosis,  211 
pollicis  a.,  211,   145,  177, 

200,  206 

scapula;  a.,  86,  384.  76,  77, 
84,     111,     185, 
343,  385 
anastomosis,  86,  384, 

385 

Dorsi-spinal  veins,  425 
Duct,  nasal,  458 

Stenson's,  522.    472,    477, 

485,  491,  504 
course,  522 
divisions,  buccal,  523 

masseteric,  523 
line,  487 
relations,  522 

Ducts,  galactophorous,  54,  55 
lacrymal,  orifice  of,  517 
lactiferous,  54,  55 
of  Meibomian  gland,  512 

orifice,   517 

Bupuytren's  contraction,  161 
Dura  mater,  of  brain,  572,  573 
attachment,  575 
blood  supply.  590 
dissection,  575 
layers,  575 
iierve  supply,  590 
processes,  581,  578 
pulsations.  575 
sarcoma.  575 
sinuses,  582,  579 
hemorrhage 

from.  583 

of     spinal     cord,      428, 
429 


E. 

Ear,  external,  465,  524 
arteries.  ~>:.!!J 
divisions,  524 
muscles,  529 

extrinsic,  469 
intrinsic,  529,  527 
pinna,  524,  525 

landmarks,  565 
Ec/ema  of  nipple,  57 
Edema  of  arm,  81 

in    carcinoma   of    mam- 
mary gland,  81 

Eighth  cervical  n.,  posterior  divi- 
sion, 410 
cranial  n.,  579 
Ellx>w,  angle  of,  17,  21 

brachial  a.  at,  328,  329 
collateral  circulation,  114 
dimple  behind,  28,  25 
dislocation,  252 
excision,  262 

structures  involved,  2G2 
landmarks.  •>-< 
ligaments,  227,  225 
limits,  :!1 

median  n..  328,  329 
nerves,  128 
triangle,  130,  131 

contents,  131 
Elbow-joint,  17,  225 

amputation  through,  288 

structures  involved,  288 
blood  supply,  228 
bursa-.  22-  ' 
formation,  224 
ligaments,  227 
movements.    17.  228 
nerve  supplv,  228 
relations,  227 
synovial  membrane,  228 
synovitis,  22« 
Eleventh  n.,  593,  579 
Embolism,  fat,  259 
Eminence,  frontal,  455 
hypotheuar,  32,  172 
parietal,  456 
thenar,  32,  171 

muscles  forming,  171 
Encephalocele,  455 
Enlargements  of  spinal  cord,  cer- 
vical, 428 
lumbar,  428 
Epiphysis  of  acromion  process,  18 

ununited,  266 
of  humerus,  fracture,  273 
Epistaxis,  507 
ICpithelioma  of  mammary  gland. 

57 

Epitrochlear  gland,  104 
Erector  spinse  m.,  399,  396 

blood  supply.  399 
insertion,  !!!>!) 
nerve  supply,  399 
origin,  399  ' 
relations,  399 
Erysipelas,   480 

Excision   of   breast,    arteries  di- 
.          vided,  58 
of  clavicle,  260 

structures  involved,  260 
of  elbow,  262 

structures  involved,  262 


Excision  of  humerus,  head,  261 
shaft,  2(i2 

structures  involved, 

262 
of  metacarpal  bones,  264 

structures  involved, 

264 
of  phalanges,  265 

structures  involved,  265 
of  radio-carpal  joint,  263 

structures  involved, 

264 
of  radius,  263 

structures  involved,  263 
of  shoulder-joint,  89,  261 

structures  involved,  261 
of  ulna,  263 

structures  involved,   263 
Excisions,  general  considerations, 

259.  260  " 
Exostosis,  260 
Expression,  facial,  460 
Extensor  brevis  pollicis  in.,  207 
carpi  radiaiisbrcvior  in.,  198, 
135,       140, 
141,       184, 
194 

action,  198 
blood       supply, 

198 

insertion,  198 
nerve     supply, 

198 

origin,   198 
relations,  198 
longior      m.,      198, 
128,       131, 
135,       140, 
141,       184, 
194,  200 
action,   198 
blood      supplv, 

198 

insertion,  198 
nerve      supply, 

198 

origin,  198 
relations,  198 
tendon,  206 
nlnaris  m.,  201,  194 
action,  202 
blood     supply, 

202 

insertion,  201 
nerve     supplv, 

202 

origin,   201 
relations,  201 
tendon,       200, 

206 
communisdigitorum  m.,  198, 

184,  194 
action,  201 
blood      supply, 

201 

insertion,  201 
nerve      supplv, 

201 

origin,  198 
relations,  201 
tendon,  2O6 
iudicis  m.,  208,  200 
action,  208 


612 


INDEX. 


Extensor  indieism.,  liluod  supply, 

insrrtion,  208 
nerve  supply,  208 
origin,   2<i-< 
relations,  208 
tendon,  206 

longns  pollicis  in..  207.     Vide 
F.xtensor     Seciindi     Inter- 
nodii  1'ollieis  Muscle, 
niiniini  digit!  in.,  201,  194 
action,   2111 
blood      supply, 

201 

insertion,  201 
nerve      supply, 

201 

origin,  201 
relations,  201 
tendon,  206 

ossis  metacarpi  pollicis  in., 
207,  194, 
200 

action,  207 
blood     supply, 

207 

insertion,  207 
nerve      supply, 

207 

origin,  207 
relations,  207 
tendon,       131, 
140,       206, 
337 

primi  iuternodii  pollicis  m., 
207,  194, 
200 

action.  207 
blood     supply, 

207 

insertion,  207 
nerve     supply, 

207 

origin,  207 
relations,  207 
tendon,       131, 

206,  337 
secrmdi  internodii  pollicism., 

207,  194, 
200 

action,  208 
blood      supply, 

208 

insertion,  208 
nerve     supplv, 

21  is 

origin,  207 
relations,  208 
tendon,      206, 

337 

tendon,  common,  169 
tendons,  209 

insertion,  210 
Extensors   of  lingers   and    hand, 

deep,  1!)7 
radial.  197 
superficial,  197 
Extra-dural  hemorrhage,  r>75,  597 

trephining  in,  598 
Extremity,    upper,   amputations, 

279 

anterior  view,  40 
arteries,  ligation,  294 


Extremitv.  upper,  arteries,  lines, 

300 

articulations.  17,  215 
bones   of,    development, 

366 

dissection.  47 
divisions,  17 
joints.  17,  215 
landmarks,  17,  18 
movements,  17 
nerves,  stretching,  311 
posterior  view.  41 
surface  markings,  17,  18 
Eye,  appendages.  512 

landmarks,  457 
Eyeball,  513 
Eyebrow,  512 

muscles,  494 
Eyelashes.  512,  515 
Eyelids,  512.  51(5 

areolar  tissue.  516 
blood  supply,  519 
lymphatics,  519 
muscles.  .ISM 
nerve  supply,  519 
veins,  519 


F. 

Face,  abscess,  490 
appearance,  456 
arteries,  460,  472,  477,  504 
dissection,  489 

incision,  461,  487 
fascia,  superficial,  490 
incision   tor  dissecting,  461, 

487 

landmarks,  456 
lymphatics,  567 
muscles,  490,  477,  491 
nerves,  555,  473,  477,   484 
skin,  489 

surface  markings,  456 
vascularity,  511 
veins,  509 
wounds,  511 
Facial  a.,   502,  472.   477,   484, 

485,  504 
anastomosis,  512 
branches,  51)7 
course,  502 
line,  487 
relations,  502 
transverse.      508,     472, 
477,   484,    504, 
542 

anastomosis,  508 
expression,  460 
nerve,  5:50,  592,  484,  485 
branches,  530 
bnccal  branch,  533,  473, 

477,  484 
course,  530 
digastric  branch,  533 
divisions  of,  facial,  530 
intra-cranial,  530 
temporal,  530 
infra-maxillary   branch, 

484 

infra-orbital      branch, 
473,  477,  484 


Facial  nerve,  malar  branch,  473, 

477, 484 

operation   to  expose,  ."::(> 
paralysis,  534 
stylo-hyoid  branch.   .'.:;:; 
supra-maxillarv  branch, 

534,  473,  477,  484 
temporal      branch,     47li. 

473,  477,  484 
vein,  50s,    477,    484,  485, 

509 

arterial  blood  in,  511 
communications,  511 
course,  511 
deep,  551 

diseases  involving,  511 
line.  487 
relations,  511 
transverse.  509 
Facies  Hippocratica,  457 
Falx  cerebelli,  581,  582,  578 

cerebri,  576,  581,  582.  578 
Fascia,  axillary,  68,  74,  59 

bicipital,  '  119,      110.    115, 
128,  131,  135,  140,  141 
clavi-pectoral,  67 
deep,  of  arm,  100 
back,  lt-8 
front,  107 
of  back,  371 
of  forearm,  101 
back,  196 
front,  129 
palmar,  158 

abscess,  158 
pectoral,  67 
infra-spinous,  380,  3K3 
lumbar,  409.  396,  397 

formation,  409 
palmar,  deep,  158,  156 

abscess,  158 
dividing  line,  37 
superficial,  153 
parotid,  520 
pectoral,  63,  59 
superficial,  of  chest,  48 
vessels,  48,  49 
of  face,  490 
of  forearm,  front,  126 
of  front  of  arm.  96 
of  hand,  front,  152 
of  pectoral  region.  49 
of  scalp,  466,  463,  467 
palmar,  153 
supra-spinous,  383 
temporal,  482,  484 

abscess  beneath,  482 
density,  482 
relations,  482 
vertebral,  394,  373,  396 
Fat  embolism.  259 

orbital,  496 
Felon,  deep,  168 

superficial,  Ki8 

Fetal  skeleton,  skiagraph,  257 
Fetus,  spinal  cord  in,  428 
Fibro-cartilage,  interartieular,  221 
interosseous,  of  carpal  joint, 

238 

Fifth  cervical  n.,  posterior  divi- 
sion, 410 

nerve,  539,  592.  559,  579 
branches,  539 


L\'DEX. 


(513 


Filuni  teriiiinale,  42H,  432,  429, 
433 

;s.     back     ol",     lymphatics. 
196 

collateral  circulation,  325 
extensor  in.  ol',  deep,  197 
radial.  197 
superficial,  197 
First  cervical  n. ,  posterior  primary 

division,  409 
u.,  5!)1 

Fissiira  palpebraruin,  512 
Fissure  of  helix,  530 

ol'  Santorini,  5:!0,  527 

of  spiual  cord,  antero-laterul, 

435 
median.       anterior, 

435 

posterior,  435 
postero-lateral,  435 
palpebral,  457,  513 
Fissures,  cereliral,  lines,  453 
Fistula,  salivary,  523 
Flap     method    of     amputation, 

281 

Flexor  brevis  minimi  digiti  m., 
179,  140, 
141,  159, 
173 

action,  179 
blood      supply, 

17!) 

insertion,  179 
nerve     supply, 

179 

origin,  17!) 
relations,  17!) 
pollicis  m.,    171,    140, 

159,  206 
action,  172 
blood     supply, 

172 
bead   of,    deep, 

171 
superficial, 

171 

insertion,  171 
nerve     supply, 

172 

origin,  171 
relations,  172 

carpi  radialis  in.,  133,  110, 
118,       131, 
135,  173 
action,  133 
blood     supply, 

133 

insertion,  133 
nerve      supply, 

133 

origin,  133 
relations,  133 
tendon,  135 
ulnaris    m.,    134,    110, 
118,       128, 
131,       135, 
140,       141, 
185,       194, 
200,  381 
action,  134 
blood     supply, 

134 
heads,  134 


Flexor  carpi  uluaris  in.  in  ampu- 
tation of  lore- 
ami,  134 
insertion,  134 
nerve      supply, 

134 

origin,  134 
relations,  134 
tendon,  173 
longus  pollicis  m.,  138,  135, 

140,  141 
action,  138 
blood      supply, 

138 

insertion,  l:;* 
ner\e      supply, 

138 

origin,  138 
relations,  138 
tendon,        167, 

140,  159, 
173 

ossis  metacarpi  minimi  digiti 
m.,  179.  I'iitit  Opponeus 
Minimi  Digiti  Muscle. 

profundus  digitoruni  m., 
137,  140, 

141,  200 
action,  138 
blood      supply, 

138 

insertion,  137 
nerve      supply, 

138 

origin,  137 
relations,  137 
tendon,        137, 
167,         159, 
166,  173 
sublimis  digitoruni  in.,  134, 

131 

action,  137 
blood     supply, 

137 

head  of,  humer- 
al, 134 
radial,      134, 
140,  141 
ulnar,  134 
insertion,  137 
nerve     supply, 

137 

origin,  134 
relations,  137 
tendon,         167, 
159,       166, 
173 
tendons,  167 

insertion,  168 

sheaths.  166 

theca,  166 

Folds  of  axilla,  27,  24 

Fontauel,  anterior,  452 

posterior,  452 
Foramen  ciccum.  579 

infra-orbital,  459,  563 
magnum,  superior,  582 
mental,  459 
occipital,  superior,  582 
of    splieuo-maxillary     fossa, 

557 

pterygo-palatine,  557 
rotundum,  557 


Foramen,  spheno-palatinc,  557 
superior  occipital,  ">s'-( 
siipra-eoudyloid,  :.'~ 
supra-orbital,  459 
Forearm,  31 

amputation,  287 

flexor  carpi   ulnaris    in. 
in,  134 

structures  involved,  287 
arteries,   145 
back  of,  dissection,  195 

fascia,  196 

muscles,  194 

nerves,  195 

veins,  101 

collateral  circulation.  325 
cutaneous  nerves,  97 
Ihscia,  101 
front  of,  dissection,  125 

fascia,  deep,  1 29 
superficial,  126 

veins,  100 

intermuscular  septum,  129 
iuterosseous   membrane,  234, 

140,  235 
landmarks,  31 
lymphatics,  129 
muscles,  130,  131 

section  of,  transverse,  286 
superficial  arteries,  129 
Formation  of  carpal  joint,  238 
of     carpo-metacarpal    joint, 

lirst  set,  242 
second  set.  •>  l."> 
of  elbow-joint,  224 
of  intermetacarpal  joints,  245 
of  lumbar  fascia,  409 
of  medio-carpal  joint,  241 
of    metacarpo-p  h  a  1  a  n  g  e  a  1 

joints,  24(i 
of  palmar  arch,  deep,  190 

superficial,  161 
of  radio-carpal  joint,  234 
of  radio-ulnar  joint,  inferior, 

233 

superior,  233 
of  scapulo-clavicuhir  joints, 

221 

of  shoulder-joint,  222 
of  steruo-clavicnlarjoint,  215 
of  suboccipital  triangle,  407 
Fossa,  antecubital,  38 
digastric,  455 
infra-clavicular,  18 
of  antihelix,  524.  525 
of  helix,  524,  525 
of  scapula,  383 
pituitary,  diaphragm,  581 
scaphoid,  of  ear,  524 
spheno-maxillary,  557 
contents,  557 
foramina,  557 
zygomatic,  557    ' 
contents,  557 

Fourth  cervical  n.,  posterior  divi- 
sion, 410 
nerve,  592,  579 
Fractures,    compound,    of   skull, 

571 

general  considerations,  269 
intercondyloid,  of  humerus, 

274 
nerve  injury  following,  274 


614 


INDEX. 


Fractures  of  acromion  process,  18, 

270 

of  carpus,  278 
of  clavicle,  269 

dis|ilacfiiieut     in,     270, 

268 

of  condyles  of  huinerus.  274 
of  coracuid  process  of  scapula, 

870 
of  coronoid   process  of  ulna, 

278 
of  humerus,  270 

intrrcoml.vloid,  274 
of  anatomic  neck,  273 
of  rondyles,  274 
of  epiphvses,  273 
of  shaft," 273 

displacement, in  272 
of  surgical  neck.  2":> 
of     tnlierosity.     greater. 

273 

snpra-condyloid,  274 
of  ruetacarpal  bones,  27H 
of  neck  of  luimenis,  273 
of  radius,  277 
of  scapula,  '-'7H 
of  olecranon  process,  278 
of  phalanges.   279 
of  radius,  277 

and  ulna,  278 
of  scapula,  270 

of  spine,  270 
of  shaft  of  humeru.o,  273 
of  skull,  base,  550 
of  spinal  column,  449 
of  ulna,  278 
of  vertebra?,  424,  449 
supra-condyloid,  of  humerus, 

274 
Front  of  arm,  dissection,  96 

muscles,  114 

of  forearm,  dissection,   125 
fascia,  126,  129 
veins,   100 
Frontal  a.,  470,  467,  472,  477, 

484,  504 
anastomosis,  470 
bone,  sinuses,  455 
diploic  v.,  571,  569 
eminences,  455 
lymphatics,  479 
sinuses,  517,  569,  573 
suture,  452 
vein,  509 
Frontalis   m.,    479,    491.       Vide 

Oceipito-frontalis  Muscle. 
Fronto-spheuoid  diploic   v.,  571, 

569 

Furrow,  nuchal,  351 
of  fingers,  37 
of  wrist,  31 
palmar,  34 

flexor,  37 
spinal,  351 


a. 

Galactophorous  ducts,  54,  55 
Galen,  vein,  578 
Gal va no-puncture  in  treatment  of 
aneurysm.  298 


Ganglion,  197 

Arnold's.  5.Vi 

•  rian.  594,  559,  579 
branches,  594 
relations,  594 

to   cavernous  sinus, 

589 

removal,  595 
Meckel's,  561.  550,  554 
of  Wrisberg.  200 
otic,  r>5.">.  554 
splieuo-palatiue,  561 
Gangrene    following     ligation    of 
arteries.  304 

rian  ganglion,  594,559,  579 
branches,  .~i!)4 
relations,  594 

to  cavernous  sinus, 

589 

removal  of,  595 
Gingivul  a..  ">4(i,  .V)!( 
Glabella,  452,  458 
Gland,  epitrochlear,   104 
lacrvmal,  517 
parotid,  520,  472,  477,  491, 

504 

contents,  521 
lobe,  carotid.  520 
glenoid.  5211 
pterygoid,  520 
removal,  522 
sensory  nerves,  521 
wounds,  522 

Glands,  axillary  lymphatic,  92 
in      carcinoma      of 
mammary    gland, 
92 

buccal,  502 

lymphatic,    auricular,  poste- 
rior, 566 
axillary,  92 
buccal.  566 
lingual,  567 
mastoid,  566 
maxillary,   internal,  567 
occipital,  566 
of  arm,  104 
of  head,  5(><i 
parotid,  521,  566 
posterior  pharyngcal,  567 
submaxillary.  5l><> 
suboccipital.  566 
mammary,  53,  55 
acinoe,  55 
ampulla:,  54,  55 
blood  supply,  57 
capsule,  54 
carcinoma,  53,  57 
epithelioma,  57 
in  males,  53 
lobes,  54 
lobules,  54 
lymphatics,  57 
nerve  supply,  57 
structure,  54 
supernumerary,  53 
suspensory  ligament,  54 
veins,  57 
Meibomian,   457,   516,  496, 

517 
ducts,  512 

orifice,  517 
of  axilla.  27 


(Hands,  sebaceous,  of  nipple.  54 
Gleno-hnmeral  ligament,  •'.•>.'.'> 
Glenoid  cavity,  219 

ligament   of   interphalangeal 

joint,  247 
of  inetacarpo-phalangcal 

joint.  •'.  In 

of  shoulder-joint,  223 
lobe  of  parotid  gland.  .">:JO 
Glosso-pharyngeal  n..  593 
Goll,  nerve  column,  4  14 
Gower's  nerve  tract,  44:i 
Great  palatine  n.,  554 
Groove,  bieipital.  27 
cephalic,  64 
for  biceps  muscle,  27 
Growth  of  bone,  '.!."><) 
Gustatory  n..  ,~>52 
(.N  iirromastia,  63 


Haller,  circulus  veuosus,  57 
Hand,  32 

abM'ess,  37 
arteries,  145 
back.  209 

arteries,  206 
dissection,  210 
superficial  veins,  101 
tendons,  206 
veins,  195 
exteusor    muscles   of,    deep, 

197 

radial,  197 
superficial,  197 
fascia,  superficial,  152 
landmarks,  32 
lines  of  arteries,  35 
palm  of,  dissection,  152 
line  for  arteries,  176 
skin,  152 
triangle,  32 
Harelip,  508 

operation,  508 

hemorrhage  in,  508 
Head,  accessory,  of  biceps  in.,  119 
coronoid,    of    pronator    radii 

teres  in.,  140,  141 
deep,  of  flexor  brevis  pollicis 

m.,  171 
of  pronator  radii  teresm., 

130 

inner,  of  flexor  brevis  polli- 
cis m.,  140 
of  triceps  m.,  128 
long,  of  biceps  m.,  114,  115, 

118 
of  triceps  in..  191,  380, 

115,  118 

lymphatic  glands,  566 
of   flexor  carpi   ulnaris  m., 

134 

sublimis   digitorum  in  , 

humeral,  134 

radial,       134, 

140,  141 
nl  nar,  134 
of  hnmerns,  27 
of  median  n. ,  123 
of  triceps  m.,  191,  380,  115, 
118 


INDEX. 


615 


Head,  outer,  of  flexor  brevis  polli- 

cis  111.,  14O 

radial,     of    flexor     sublimis 
digitorum    in.,    134,    140, 
141 
short,  of  biceps  m.,  119,  115, 

118 
superficial,    of  flexor  .  brevis 

pollieis  in. ,  171 
of  pronator    radii    teres 

m.,  i:JO 
veins,  529 
Helicis  major  in.,  .V.'!),  527 

minor  m.,  529,  527 
Helix,  524,  525,  527 
fissure,  530 
fossa,  5:34,  525 
Hematoma  of  scalp,  481 
Hemorrhage,  extra-dural,  575.  597 

trephining  in,  598 
following  ligatiou  of  arteries, 

304 

from  artery  of  septum,  507 
from  carpal  arch,  180,  187 
from  sinus  of  dura,  583 
in  abscess  of  axilla,  79 
in  operation  for  harelip,  508 
into     pterygo-maxillary     re- 
gion, 556 
Horizontal     division     of     lateral 

sinus,  584 
Homer's    m.,  497.     Vide  Tensor 

Tarsi  Muscle. 
Huguier,  caual,  555 
Humeral  branch  of  aeromio-tho- 

racic  a.,  85 
anastomosis,  85 
head  of  flexor  snblimis  digi- 

tornm  m.,  134 
Humerns,  centers  of  ossification, 

266 

condyles,  28 
development,  266 
dislocation,  18,  248,249 
subclavian,  251 

structures  involved, 

251,  252 
subcoracoid,  251 

structures  involved, 

251,  252 
subglenoid,  27,  248 

structures  involved, 

248,  252 
excision  of  head,  261 

of  shaft,  262 
fracture,  270 

intercoiidyloid,  274 

of  condyles,  274 

of  epiphysis,  273 

of  neck, '273 

of  shaft.  273 

of    tnberosity,     greater, 

273 

supra-condyloid,  274 
head,  27 
nutrient  a.,  114 
tuberosity    of,    greater,    27, 

185 

lesser,  27 
Hunter's  method  of  treating  aneu- 

rysm.  297.  295 
Hypo-glossal  n.,  593 
Hypothenar  eminence,  32,  172 


I. 

Iliac  crest,  362 

Ilio-costalis  m.,  3!)9,  396,  397 
action.    :!!>!> 
insertion.  399 
nerve  supply,  399 
origin,   399 
relations.  399 
Impulse,  motor,  450 
course,  450 
sensory,  450 

course,  450 

Incision  for  abscess  of  axilla,  79 
In-east,  58 
parotid,  522 

for  dissection  of  back,  365 
of  face,  461,  487 
of  neck,  487 
for  exposing  axillary  a.,  64 
facial  n.,  536  * 
infra-orbital  n.,  563 
for  ligatiug  axillary  a.,  301 
brachial  a  .  301 
radial  a.,  301 
subscapular  a.,  301 
uluar  a.,  301 
for  musculo-spiral  n.,  94 
for  parotid  abscess,  522 
for   posterior   circumflex  a., 

41 

for  radial  u.,  301 
for  removing  growth  of  ax- 
illa, 81 

for  stretching  brachial  plex- 
us, 301 
median  n..  301 
for  ulnar  n.,  301 
Wilde's,  455 
Incisive  a.,  547.  546 

branch  of  mvlo-liyoid  n.,  555, 

559 

Incisura  iutertragica.  524,  525 
Infants,  mammary  gland,  63 
Inflammation  of  periosteum,  260 
of  scalp.  481 
of  sheath  of  flexor  tendons, 

157 

of  subacromial  bnrsa,  223 
Infra-clavicular  fossa.  18 
triangle,  deep,  73,  71 
contents,  73 
dissection,   73 
superficial.  67,  70 
dissection,  67 
Infra-maxillary  branch   of  facial 

n.,  534,  484 

Infra-orbital  artery,  540,  548, 
484,  542,  546,  550, 
559 

anastomosis,  540 
branch  of  facial  n.,  533,  473, 

477,  484 
foramen.   459,  563 
margin.  4.V 
nerve,   539,  561,   473,  484, 

559 

branches.  539,  561 
labial,  539,  484 
nasal,  539,  484 
palpebral,  539,  484 
operation  to  expose,  563 
structures  involved, 
563 


Infra-orbital    plexus    of    nerves, 

533,  539 
vein,  540 
Infra-spiuatus  m.,  383,  184,  185, 

373,  381 
action,  383 
blood  supply,  383 
insertion,  383 
nerve  supply,  383 
origin,  383 
relations.  383 

Infra-spinons  fascia.  :!>().  383 
Infra-trochlear    u.,     473,     477, 

484 

Infusion,  saline,  104 
Inion,  455 

Injuries  to  spinal  cord,  449 
Innominate  v.,  509 
luterarticular  cartilage,  216.  214 

fibro-cartilage,  221 
Intercarpal  joints,  238,  231,  235 
blood  supply,  242 
ligaments,  238 
movements,  242 
nerve  supply,  242 
ligaments,  anterior,  235 
Interclavicular     ligaments,    216, 

214 

relations,  216 

Intercondyloid     fracture    of    bu- 
rn eras,  274 
displacement,  274 
structures  involved, 

274 
Intercostal     branch     of    internal 

mammary  a.,  48 
muscles,  external.  391 

internal,  391 
nerve,  87 
vein,  425 
Iiitercosto-humeral   n.,    91,    188, 

59,  76,  77,  97 
Intermetacarpal  joints,  245 
blood  supply,  246 
formation.  2-45 
ligaments,  245 
nerve  supply,  246 
Intermuscnlar  septa  of  arm,  107 
septum  of  arm,  external,  107 

internal,  107,  110 
of  forearm,    129 
Interosseous  a..    :!7,    140,    141, 

159,  173 
anterior,  147,  140,  141, 

145,  177,  203 
common,  147,  140,  141, 

145,  203 

dorsal.  145,  177,  206 
first,  211 
line,  176 

palmar,  180,  145,  177 
anastomosis,  180 
course,  180 

posterior.  208, 140, 141, 
145,  194,  200, 
203 

anastomosis,  208 
branches,  208 
relations,  208 
recurrent,     208,       111, 

145,  200 
second,  210 
third,  210 


616 


INDEX. 


Interosseoiis  libro-cai  tilage  of  car- 
pal joint,  •>'.',* 

ligament  of  carpal  joint,  :2I1 
of  carp o-ni ct aca  rpal 

joint,  :M"i 
of  intermetacarpal  joint, 

246 

membrane   of   forearm,    1-13, 
234,  140,  145,  203,  230, 
235 
miiM-le.  169 

dorsal,  311,  173,  206 
action,  212 
blood  supply,  212 
insertion,  211 
nerve  supply,  211 
origin,  212 
relation,  212 
insertion,  169 
palmar,  leT,  141,  173 
action,  187 
blood  supply,  187 
insertion,   1>7 
nerve  supply,  187 
origin,  187 
nerve,   anterior,   of  median, 

148 
posterior,  209, 135, 140, 

141,  200,  203 
brandies,  209 
relations,  209 
Interpalpebral  slit,  512 
luterphalangeal  joints,  -217 
blood  supply,  247 
ligaments,  247,  244 
movements,  247 
nerve  supply,  247 
position  of,  37 
synovial  membrane,  247 
Interspiuales  m.,  404 
action,   407 
blood  supply,  403 
insertion,  404 
nerve  supply,  407 
origin,  404 

Interspinons  ligament,  416,  413 
Intersiitural  membrane,  481 
Intertrausversales  m.,  407 
action,  407 
blood  supply,  403 
cervical,  407 
insertion,  407 
lumbar,  407 
nerve  supply,  407 
origin,   407 
relations,  407 
tboracic,  407 

Intertransverse  ligament,  416 
Intervertebral    discs,    412,    413, 

425 
Intro-cranial  division  of  facial  n., 

530 
nerves,  591 

course,  591 

neurectomy  of  inferior  maxil- 
lary n.,  594 
of  superior  maxillary  n., 

594 
Intra-thecal     course     of     spinal 

nerves,  435 

Intrinsic  m.  of  pinna,  527 
Irritation  of  circumflex  u.,  314 
of  median  n.,  314 


Irritation    of    musculo  spiral   n., 

314 

of  ulnar  n.,  ill  1 
Iter  chorda'  anterius,  555 


J. 

Joints,  212.      Vide  Articulations. 
Jugular  v.,  anterior,  509 

external,  509 
line,  487 

internal.  509 

posterior.  509 


K. 

Keratosis  senilis.  457 
Kidneys,  position,  36'2 
Knuckles.  :!7 

landmarks,  37 
Kyphosis,  352,  358 


Labial  a.,  inferior.  507,  472,  477, 

504,  546 
anastomosis.  507 
branch    of    infra-orbital    n., 

539,  561,  484,  559 
Laerymal  canalienli,  512,  517 
caruncle,  513 
duets,  orifice  of.  517 
gland,  517 
nerve,  539 
punctum,  513 
sac,  45«,  517 

abscess,  508 

Lactiferous  duets,  54,  55 
Lacuna;  lateral  is,  583 
Lacus  lachrymal!?,  512 
Lambda,  452 
Lambdoid  suture,  452 
Landmarks  of  arm,  27.   21,  24, 

25 

of  auricle,  405 
of  axilla,  :27 
of  back,  353 
of  neck,  351 
of  shoulder,  352 
of  trunk,  351 
of  cranium,  451,  453 
of  ear,  565 
of  eye,  457 
of  face,  456 
of  forearm,  31 
of  hand,  32 
of  knuckles,  37 
of  neck,  351 

of  back,  351 
of  pinna,  565 
of  shoulder,  352 
of  back,  352 
of  trunk,  351 

of  back,  351 
of  upper  extremity,  17 
Lateral  atlanto-axoid  joint,  419 
sinus,  584,  578,  579 
course,  456 
divisions,  584 
line,  587,  585 
thrombosis,  584 
tributaries,  584 


Lateralis  nasi  a.,  .MH 

anastomosis,  508 

Latissimus  dorsi  in..  '.',~~>,  62,  65, 
70,  71,   76,    77, 
343,  373 
action,  :!7(! 
aponenrosis,       373. 

396 

blood  supply,  376 
insertion,  375 
nerve  supply,  376 
origin,  '.',!'> 
relations.  .'i7ii 
tendon,  185 
Layers  of  dura  mater  of  brain,  575 

of  scalp,  465 
Leeching,  5*  1 

Length  of  arms,  comparative.  1- 
Lesioiis  of  spinal  cord,    I  Hi 
Levator  anguli  oris  m.,  500,  491 
action,  500 
insertion,  500 
nerve      supply, 

500 

origin,  500 

scapulae  m.,  377,  87,  373 
action,  377 
blood      supply, 

377 

insertion,  377 
nerve      supply, 

377 

origin,  377 
relations,  377 
labii  inferioris  in.,  500 
action,  500 
insertion,  500 
nerve      supply, 

500 

origin,  500 

superioris  alo;que  nasi 
m.,  493, 
491 

action,  493 
insertion, 

493 

nerve   sup- 
ply, 493 
origin,   493 
relations, 

493 

muscle,  409,  491 
action,  499 
insertion,  499 
nerve      supply, 

41)0 

origin,  499 
relations,  499 

meuti  m.,  491.     ride  Leva- 
tor  Labii  Inferioris  Muscle, 
palpebrse  superioris  m     519, 

517 
insertion,     498, 

519 

origin,  519 
relations.  520 

Levatores  costarum  m.,  40),  397 
action,  404 
blood  supply,  403 
insertion,  404 
nerve  supply,  404 
origin,  404 
relations,  404 


IXDKX. 


617 


lent,  accessory,  of  shoulder, 

•  >•>;; 
acromio-clavicular,     inferior, 

221.  218 

superior,  221,  218,  219 

auuular,   of   wrist,    anterior. 

129,  157,173, 

159,  230 

compartments, 

167 

relutions,  157 
posterior,    129.    196, 

194,  206 
compartments, 

197 

anterior  atlanto-axoid,  419 
of  elbow.  227,  225 
of  interphalangeal  joint, 

247 
of  metaearpo-phalangeal 

joint,  246 

of  Ridio-curpal  joint,  237 
atlanto-axoiil,  415 

anterior,  419.  417 
capsnlar,  417 
posterior,  419 
superlicial,  419 
capsular,     of      atlanto-axoid 

joint,  119,  417,  421 
of  carpal  joint,  238 
of       carpo-metacarpal 
joint,  245,  230,  231 
of  occipito-atlantal  joint, 

423,  417 
of     radio-carpal     joint, 

235 
of    shoulder-joint,     223, 

218 
of    vertebra?,    415,    416, 

413,  417 
carpal,  dorsal,  231 
carpo-metacarpal,     anterior, 

235 

cervico-hasilar,  420,  421 
check,  423 

common,  anterior,   of  verte- 
bras, 417 
posterior,     of   vertebrae, 

412,  413 

conoid,  221,  218,  219 
coraco-acromial,      27,     222, 

115,  118,  218,  219 
eoraeo-clavicular.  221 
coraco-humeral,  223,  218 
costo-clavicnlar,  216 
crucial,      of      atlanto-axoid 

joint,  420,   421 
dorsal,  of  carpal  joint,  238, 

241 
of     carpo-m  etacarpal 

joint,  242 
of  intennetacarpaljoint, 

245 

external  tarsal,  494 
gleno-humeral,  223 
glenoid,  219 

of  interpbalangeal  joint, 

247 
of  metacarpo-phalangeal 

joint,  246 
of  shoulder,  223 
inferior     aeromio-clavicular, 
221,  218 


Ligament,    inteivarpal,    anterior, 

235 
interclavicular,  216,  214 

relations.  216 
internal  lateral,  of  lower  jaw, 

543,   542,  550 
tarsal,  494 
interosseons.  of  carpal   joint, 

241 
of    carpo-metacarpal 

joint.  :.'  15 
of  internietacarpal  joint, 

246 

iuterspinous,  416.  413 
intertrausverse,  416 
lateral     external,    of    elbow, 
-227,  225 

of  medio-carpal 

joint.  242 
of   ra  d  i  o-c a  rpa 1 

joint,  237 

of  wrist.  230,  231 
internal,  of  elbow-joint, 

227,  225 
of  HUM!  io-carpal 

joint,  242 
of    rad  i  o-car pal 

joint.  237 

of  wrist,   230.   231 
of  interphalangeal  joint, 

247 
of  metacarpo-phalangeal 

joint,  246 
of' thumb,  247 
of  vertebne,  415 
medio-carpal,  anterior,  241 

posterior.  241 
metacarpal,  166 
oblique,  143,  234,   145,  225 
occipito-atlantal,  415 
anterior,  423,  417 
obli(|iie,  417 
capsnhir,  417 
lateral,  423,  417 
posterior,  423.  406,  417 
occipito-axoid,  420 
occipito  cervical,  420 
occipito-odontoid,  420,  421 
odontoid,  420 
of  atlanto-axoid  joint,  419 
of  carpal  joint,   238 
of     carpo-metacarpal     joint, 

first  set,  242' 
second  set,  245 
of  elbow-joint.  227 
of  intermetacarpal  joint,  245 
of  interphalangeal  joint,  247, 

244 

of  medio-carpal  joint,  211 
of  metacarpo-phalangeal 

joint,  246.   244 
of  occipito-atlantal  joint,  423 
of  occipito-axoid  joint,  420 
of  radio-carpal  joint,  234 
of  radio-ulnar  joint,  233 
of  scapula,  222 
of   scapulo-elavicular    joint, 

221 

of  shoulder-joint,  223 
of  Sir  Astley  Cooper,  54 
of  spinal   column.  412,  413 
of  sterno-clavicnlar  joint,  216 
of  vertebra?,  412 


Ligament   of    vertebral   column, 

412 

orbicular,  225 
orbito-tarsal,  516 
palmar,   of  carpal  joint.  238, 

241 
of  carpo-metacarpal 

joint,  242 
of  intermetacarpal  joint. 

245 

palpebral,  516 
piso-metacarpal,  241 
piso-uncinatc,  241 
posterior  annular.    129.   I'M, 

194,  206 
compartments,  197 
atlanto-axoid,  41!) 
of  elbow-joint,  227,  225 
of  radio-carpal  joint.  2::" 
of  thumb,  247 
ptcrygo-max illary,  501 
radio-carpal,    anterior.     2117. 

230,  235 
external,  237 
posterior,  237,  231 
radio-ulnar,      anterior,     233. 

230,  235 
posterior.  233.  231 
rhomboid,  216,  214 

relations,  216 
sterno  clavicular,   a  n  t  erior, 

216,  214 
relations,  216 
posterior,  216,  214 

relations,  216 

superficial  atlanto  axoid,  419 
superior    acromio-cla\  icnlar, 

221,  218,  219 
supra-scapular,  222 
supra-spinous,  415,  396,  413 
suspensory,  of  axilla,  08 
of  mammary  gland,  54 
of    occipito-axoid   joint, 

420 

tarsal,  494 

transverse  metacarpal,  37 
of    atlanto-axoid     joint. 

420 
of  intermetacarpal  joint, 

246 
of   scapula,    222,    218, 

219 

superficial,  of  hand,  152 
trapezoid,  221,  218,  219 
nlno  carpal,  237 
vaginal,  of  fingers,  167 
vertebral,   412,  417 
Ligamenta  brevia,  168,  166 
longa,  168.  166 
snbtlava.  415.  417 
Ligamentiim  arcuatum  externum, 

409 
denticulatum,       432,      429, 

433 

nuchse,  375,  415,  373,  396 
Ligation  of  arteries,  gangrene  fol- 
lowing, 304 
general     considerations, 

303 
hemorrhage     following, 

304 

of  upper  extremity,  294 
of  artery  and  vein,  81 


618 


I XI)  EX. 


Ligation  of  axillary  a.,  -"i.  304 

collateral      circula- 
tion. 306 
of  brachial  a..  301 

collateral        circula- 
tion, :;i)8,  3<i9 
structures  involved, 

307 
of  circumflex   a.,    posterior, 

306 
structures     i  n  - 

volvecl,  3U6 
of  radial  a.,  310 

collateral       circula- 
tion, HID 
structures  involved, 

310 
of  subscapular  a.,  306 

structures  involved, 

306 
of  ulnar  a.,  311 

collateral       circula- 
tion, 311 
guide,  134 
structures  involved, 

311 

of  veins,  si 
Ligatures  in  treatment  of  ancu- 

ry.sms.  21)7 
Liue,  Keid's  base,  453 

to  expose  radial  a.  ill  snuff- 
box, 337 

Linen  splemlens,  432 
Line;e  semilunaris.  52 

transversie  of  ubdomeii.  52 
Lines  for  arteries  of  band,  35 
of  palm,  176 
of  upper  extremity,  122, 

300 

for  axillary  a.,  45,  81 
for  brachial  a.,  108,  122.  300, 

307 

for  carotid  a.,  common,  487 
for  collateral  digital  a.,  176 
for  common  carotid  a..  487 
for  deep  palmar  arch,  122, 

176,  300 
for  digital  a.,  176 

collateral,  176 
for  external  jugular  v.,  487 
for  facial  a. .'487 

vein.  487 
for  incision  to  expose  mus- 

culo-spiral  n.,  41 
for  intcrosseons  a.,  176 
tor  jugular  v.,  external,  487 
for  lateral  sinus,  587,  585 
for  longitudinal  sinus,  supe- 
rior, 583 

for  median  n.,  122,  300 
for  palmar  arch,  deep,  122, 

176,  300 
superficial,      122, 

176,  300 
for  posterior  circumflex  a., 

41 

for  princeps  pollicis  a.,  176 
for  radial  a.,  143,  309,  122, 

176,  300 

for  radialis  indicis  a.,  176 
for  sigmoid  sinus,  151,  585, 

587 
for  Stenson's  duct,  487 


Lines  for  suliscapular  a..  si; 

for    superficial    palmar  arch, 

122,  176,  200 
for     snperticialis     vola;     a., 

176 
for  ulnar  a.,  141,  122,  176, 

300 

nerve,  312,  122,  300 
of  cerebral  fissures,  453 
Lingual  lymphatic  glands,  f>(i7 
nerve'.  552,  542,  550,  559 

brandies.  55:2 
vein,  509 
Lister's   method   of  amputation, 

282 
Lobes  of  mammai  v  gland,  54 

of  parotid  glaiid.  52o 
Lobule  of  ear.  521.  525 
Lobules  of  mammary  glaml,  54 
Long  huccal  »..  552 

thoracic  a.,  53,  76 
Lougissimus  dorsi  m.,  400,  396, 

397 

action,   400 
blood  supply,  400 
insertion,  4oo 
nerve  supply,  400 
origin,   400 
relations,  400 
Longitudinal  sinus,  inferior,  588, 

578 
superior.  583,  573,  578, 

579 

course,  45(i 
line,  583 
wounds,  5-'3 

Longus  colli  m.,  nerve  to,  87 
Lordosis,  352.  358 
Lumbar  abscess,  356,  409 

enlargement  of  spinal  cord, 

428 
fascia.    Id!).  386,  397 

formation,  409 
intertransversales  m.,  407 
nerve,  origin,  361 

posterior  division,  410 
vertebrae,  abscess,  356 
caries,  356 
spines,  361 

Lumbricales  m.  of  hand,  lii-\ 
140,  159,  169, 
173 

action,   168 
blood  supply,  168 
insertion,  168,  169 
nerve  supply,  168 
origin,   168 
Lymphatic      glands,     auricular, 

566 

huccal,  566 
lingual.  567 
mastoid,  566 
maxillary,  567 
occipital,  566 
of  arm,  104,  105 
of  axilla,  92 

in      carcinoma     of 

breast.  92 
of  head,  566 
parotid,  521,  566 
posterior  pharyngeal,  567 
submaxiliary,  566 
suboccipital,  566 


Lymphatics,  auricular,  posterior, 

479 

frontal,    17!) 
occipital.    17(1 
of  arm.  loi.  105 
of  evelicls.  51!) 
of  face.  567 
of  fingers,   1!)5 
of  mammary  gland.  57 

anastomosis,  57 
of  pectoral  region.  53 
of  pinna,  5:2!l 
of  pterygo-maxillary   region, 

551 

of  scalp,  476,  567 
posterior  auricular,  479 
superficial,  of  forearm.  12!) 
of  upper  extremity,  104, 

105 
temporal,  479 


M. 

Main  en  grifife,  277 

Malar   branch  of  facial  u.,   473, 

477,  484 
of  orbital  n.,  55s 
of  temporo-facial  n..  533 
of  temporo-malar  n.,  540 
Mamma,  53,  55 
Mammary  abscess.  5- 

artcry,  deep  external,  58,  85 
internal,  anastomosis,  85 
brandies.  4< 
perforating    branch, 

49 

gland,  53,   55 
abscess,  58 
absence,  63 
aciiuc,  55 
adhesions,  58 
ampulhe.  54.  55 
anomalies,  63 
blood  supply,  57 
capsule,  54 
carcinoma.  53,  57 

course  of  metastasis, 

57 

epithelioma,  57 
excision,  58 
in  infants,  (13 
in  males,  53 
lobes,  54 
lobules,  54 
lymphatics,  57 

anastomosis,  57 
nerve  supply,  57 
structure,  54 
supernumerary,  53,  63 
suspensory  ligament,  54 
tumors,  58 

Spence's  test,  58 
veins,  57 

Mammilla,  54.     Vide  Nipple. 
Marrow  of  bone.  259 
Masseter  m.,  523,  485,  491 
action,  524 
blood  supply,  524 
insertion,  523 
nerve  supply,  524 
origin,  523 
relations,  523 


INDEX. 


619 


Masseterica..  548.  484.  542,  546 
nerve,   .V>1,  485,  542 
port  ion  <>r  Stciison's  duet,  5:23 
Mastoid    branch   of  priuceps  cer- 

vicis  a.,   UK; 
lymphatic  glands,  566 
process,  455 

operations,  587 

Maxillary  a.,  internal,   543,  544, 
484,    485,    542, 
546,  550,  559 
brandies.  547,  546 
divisions,  547 
division  of  internal  maxillary 

a..  547 

Ivmphatic   glands,    internal, 
'  567 
nerve,  inferior,  551,  594,  550, 

559, 579 
brandies,  551 
neurectomy   of,    in- 
tracranial, 
594 

structures      in- 
volved, 594 
superior,   557,   562,  594, 

542,  550,  579 
branches,  558 
course,  557 
infra-orbital  branch, 

473 

neurectomy  of,  in- 
tracranial, 
594 

structures      in- 
volved, 594 
vein,  anterior,  551,  509 

internal,  551,  509 
Measurements  of  arm,  47 
Meckel's  ganglion,  561,  550,  554 
branches,  561 
removal,  563 

structures  involved, 

563 

space,  594 
Median  a.,  148,  140 

of  spinal  cord,  444 
basilic   v.,    103,    100,    110, 

128 
cephalic  v.,  103,  100 

infusion  into,  104 
nerve,  91,  123,  148,  162,  76, 
77,    87,    110,     115, 
118,  128,  131,  135, 
159 

branches,  123,  148,  162 
course,  38 
cutaneous  branch,  129 

palmar,  97 
divisions,  162 
heads,  123 
incision   for    stretching, 

301 

irritation,  314 
line,  122,  300 
motor  points,  40 
operation      to      expose, 
316,      317, 
319 
above         wrist, 

349 

relations.  123,  148,  316, 
317 


Median  nerve,  relations,  at  elbow, 

328,  329 
stretching,  312,  313 

structures  involved, 

312,  313 

vein,  126,  100,  128 
deep,  100,  128 
Medio-carpal  joint,  241 

ligament,  anterior,  241 

posterior,  '.1 1 1 
Medulla  spinalis,  428 
Medulli-spimil  v.,  427 
Meibomiau  inlands,  457,  516,  496, 

517 
ducts,  512 

orifice,  517 

Membrana     uictitaus,     rudimen- 
tary, 515 
Membrane,      costo-coracoid,     68, 

62,  70 
iuterosseous.   143,   234,   141, 

145,  203,  230,  235 
intersutnral,  481 
of  brain.  568 
of  spinal  cord,  428,  429 
synovia!,  215 

of    atlanto-axoid    joint, 

419,  417 

of  carpal  joint,  241 
of  carpo-metacarpal 

joint,  245 
of  carpus,  228 
of  elbow-joint,  228 
of  iutermetaoarpal  joint, 

246 
of  interphalangeal  joint, 

247 
of  metaearpo-phalangeal 

joint,  246 
of     radio-ulnar     joints, 

237 

inferior,  234 
superior,  233 
of  shoulder-joint,  223 
Meuiugeal  a.,  anterior,  598 

middle,  456,  547,  597, 
546,  550,  554. 
559,  573,  578, 
579 

brandies,  597,  598 
wounds,  598 
posterior,  599 
small,   547,   599,     546, 

550,    559 
vein,  599 

Meningitis,  spinal,  451 
Meningocele,  455 
Meningo-rachidian  v.,  427,    425 
Mental  a.,   540,  547,   484,  546, 

559 

anastomosis,  540 
branch    of     mylo-hyoid   n., 

555,  559 
foramen,  459 

nerve.  540,  473,  484,  550 
Metacarpal   a.,    211,   145,   200, 

206 
bones,  169 

development,  269 
disarticulation,  284 

structures  involved, 

284 
dislocation,  255 


Metacarpal  bones,  excision,  264 

structures  involved, 

264 
fracture,  27* 

displacement,  278 
structures  involved, 

278 

position  of  heads,  37 
ligaments,  transverse.  166 
Metacarpo-phalangeal   joint,    17, 

246 

blood  supply,  246 
formation,  246 
ligaments,  246,  244 
movements,   17,  246 
nerve  supply,  246 
synovia!  membrane,  246 
Metacarpus,    centers    of    ossifica- 
tion, 269 

Metastasis,    course    of,   in   carci- 
noma of  breast,  57 
Method  of  amputation,  circular, 

280 

modified,  280 
flap,  281 
Lister's,  282 
oval,  283 
Spence's,  282 
Teale's,  281 
of       treating       aneurysms, 

Anel's,  297 
Antyllus',  297,  295 
Brasdor's,  297,  295 
coagulating   m  a  t  e  - 

rial,  298 

foreign  body,  298 
ga  1  v  an  o-puncture, 

298 

Hunter's,  297,  295 
manipulation,  298 
pressure,  297 
"VVardrop's,     297, 

295 

Micromazia,  63 
Miner's  elbow,  188 
Mobility  of  scalp,  480 
Montgomery,  tubercle,  54,  55 
Motor  areas  of  spinal  cord,  445 
impulse,  voluntary,  450 

course,  450 
oculi  n.,  579 
points,  47 

of  brachial  nerve  plexus, 

40 

of  circumflex  n. ,  41 
of  median  n. ,  40 
of  musculo-spiral  n..  40 
of  posterior  iuterosseous 

n. ,  41 

of  subscapular  n. ,  40 
of  ulnar  n. ,  40 
tracts  of  spinal  cord,  degen- 
eration in,  450 
Mouth ,  458 

muscles,  498 
Multifidus  spinse  m.,  404,  397, 

406 

blood  supply,  403 
insertion,  404 
nerve  supply,  404 
origin,  404 

Muscle,    abductor    iudicis,    211, 
159,  173,  206 


620 


L\DKX. 


Muscle,    alnluctor  iiiiniiiii  digiti, 

172.  140,  141,   159, 

173,  206 

pollicis,    17,    140,   141, 

159 

aecessorias,  :','.>'.>.  396,  397 
ad    ilio-eostulem.       I'iilc 

Aceessorins  Muscle, 
adductor  i>ldii|iie,  of  thumb, 
171.        I'iile    Flexor 
Brevis    Pollicis    Mus- 
cle, 
pollicis,  17-2,  140,  141, 

159,  206 
anconens,    202,    184,    194, 

200 

anterior  dilator  nariuni,  491 
antitragiens,  5:39,  527 
;itt<>lfiis  aiin-ni.    Hi!).  491 
attrahens  aurcm,  469,  491 
axo-appendicular,  411 
biceps,  '27,  114.  119,  70,  76, 
77,  110,  115,   128,  194, 
200 

biyenter  cervicis,  402 
brachialis  anticus,  120,  115, 
118,128,  131,135,140, 
141,  184,  194,  200,  345 
brachio-radialis,  197 
buccinator,   501,    485,    491, 

542,  550 
cervical  is     ascendcns,      400. 

396,  397 
ciliary,  of  orbicularis  palpe- 

brarnni.  497 
complexns,   401,   373,   396, 

397 
compressor  uariiim,  491 

minor,  491 
nasi,  493 
coraco-brachialis,     120,     65, 

70,  76,    77,   110,    115, 
118 

corrugator     supercilii,     498, 

496 

cranio-vertebral,  407,  411 
deltoid,  27,  378,  24,  65,  70, 

71,  76,    77,    110,    115, 
118,  184,  341,  373 

depressor  a  he  nasi,  494 
angti  I  i  oris,  491 
labii  iulenoris,  500,  491 
dilator  naris.   193 

nariuni,  anterior,  491 

posterior.  491 
erector  spimu,  399,  396 
extensor  brevis  pollicis,  207. 
t'iil/    Extensor   Primi 
Internodii   Pollicis 
Muscle. 

carpi     radial  is    brevior, 
198,        135, 

140,  141, 
194 

longior,  198, 
128,  131, 
135,  140, 

141,  184, 
194,   200 

nlnaris,  201,  194 
communis       digitorum, 

198,  184,  194 
indicia,  208,  200 


Muscle,  extensor  lonuus  pollicis. 

207.        I'iilt     K\ten>or 

Sccunili    Internodii 

Pollicis  Muscle. 

minimi  digiti,  201.  194 

ossis   metacarpi    pollieis. 

207,  194,  200 
primi  internodii  pollicis, 
207,  194,  200,  337 
secundi  internodii  polli- 
cis. 2(17.  194,  200 
external    oblii|ue.    52,     65, 

373,  396 
ptervgoid,  543,  542 
flexor   brevis  minimi    digiti, 
179.     140,     141, 
159 
pollicis,    171,    159, 

206 
carpi  radialis.  133.  110, 

118,  131,  135 
ulnaris,    131,     110, 
118,    128,    131, 
135,   140,    141, 
185,  194,  208 
longus  pollicis,  138,135, 

140,  141 

ossis    mctacarpi    minimi 

digiti,  179.      Vide  Op- 

ponens  Minimi  Digiti 

Muscle. 

prol'nndus    digitorum, 

137,  140,  141,  200 
sublimis  digitorum,  134, 

131,  135 
frontalis,  479.    Vide  Occipito- 

frontalis  Muscle, 
helicis  major,  529.  527 

minor.  529,  527 
Homer's   497.      Vide.  Tensor 

Tarsi  Muscle. 

ilio-costalis,  399,  396,  397 
inferior  oblique,  496 

rectus,  496 
infra-spinatus,     383,     184, 

185,  341,   373,  381 
intercostal,  external,  391 

internal.  391 
internal    oblique,    52,    373, 

396 
pterygoid,      544,     542, 

554,  550 

interosseous,  of  hand,  141 
latissimus    dorsi,     375,     52, 
62,   65,   70,  71,   76,  77, 
373 
levator  anguli  oris.  500.  491 

scapulae,  377,  373 
labii  int'erioris,  500 

snperioris,  499,  491 
akeqne      nasi, 

493,  491 
menti,  491 
palpebrx  snperioris,  519, 

517 
longissimus  dorsi,  400,  396, 

397 

masseter,  523,  485,  491 
mill  ti  fid  us  spinse,  404,  397, 

406 

mnsculus  caninus.  Vide 
Levator  Angnli  Oris  Mus- 
cle. 


Muscle,    oblique,     external,     52, 

65,  396 
inferior,   496 
internal.  52,  396 
obliqnus  anris,  529,  527 

capitis    inferiiiris.     408, 

397.  406 
superioris,  408,396, 

397,  406 
occipitalis.  17!).      [  iil<  Occip- 

ito-frontalis  Muscle. 
occi|>ito-lrontalis,  479 
omo-hyoid,  65 
opponens  minimi  digiti,  179, 

141,  173 
pollicis.  171,   140,   141, 

159 

orbicularis  ocnli.    Vide  Orbic- 
ularis    Palpebrarnm 
Muscle. 
oris,  498,  491 
palpebrarnm,  494,  491 
palmaris  brevis,  152.  156 
longn~.    133.    110,  128, 

131,  135 

pannicnlus  carnosus,  48 
pcctoralis  major.  (i3,  52,  62, 
65,   70,   71,   76,   77, 
110 

minor,  73,  62,  65,  76 
platysma  myoides,  48,   485, 

491 
] posterior  dilator  nari urn,  491 

scapular,  381 
prouator      qnadratns,      138, 

135,  140,  141 
radii    teres,     130,    118, 
128,  131,  135,  140, 
141 

pterygoid,  external,  543,  542 
'internal,  544,  542,  550, 

554 

pyramidalis  nasi,  490,  491 
quadratns  menti.      Vide  De- 
pressor    Labii      Inferioris 
Muscle. 

reetns  capitis  ]>osticus  major, 
408.         397, 
406 
m  i  n  o  r,       408, 

397,  406 
inferior,  496 
sternalis,  (>'4 
superior.  496 
retrabens  anrem,  4(>9.  491 
rhonihoideus  major,  377,  373 

minor,  377,' 373 
risorins,  498,  491 
sacro-lunibalis.       Vide    Ilio- 
costalis  Muscle. 
Santorini's.       Vide    Eisorins 

Muscle. 

sealenus  posticns.  396 
semispinalis  colli,  403,  406 
dorsi,    403,    396,    397, 

406 

serratus    magnus,     387,    52, 
65,  71,  76,  77,  373, 
391 
posticus  int'erioris,   394, 

373,  396 
superioris,  393,373, 
396 


INDEX. 


621 


.Muscle,  sphineterocnli.     I'iili  Or- 
bicularis  Palpebrarum 
.Muscle, 
oris.        I'iili    Orhiciilaris 

( Iris  Muscle, 
spinalis  colli,  401 

dorsi,  401,  396,  397 
splcnius,  394 

capitis,  373,  396 

el  colli.      I'iilr  Sple- 

nius  Muscle, 
eolli.  373,  396 
sterno-hvoid,  65 
stemo-maatoid,  65,  373 
sterno-thyroid,  65 
subaiiciiiicus.  192 
subclavius,  68,  62,  71 
subscapularis.   387,    62,    65, 

71,  76,  77,  343,  390 
superior  reetus,  496 
supiuator  brevis,    202,   135, 

140,  141,  200 
longus,   197,   110,   115, 
118,  128,  131,  135, 
140,  141,   184,  194, 
200,  345,  347 
radii  brevis.     fide  Supi- 
nator     Brevis 
Muscle. 

longus.      fidf  Snpi- 
nator    Longus 
Muscle, 
supra-spinatus,     383,      184, 

185,  373,  381 
temporal,     489.     485,    542, 

550 
tensor  palati,  554 

tarsi.  497,  496,  517 

teres   major,    380,    62,    65, 

76,    77,     110,     184, 

185,  343,  373,  390 

minor,    3SO.    184,   185, 

341,  373 
trachelo-mastoid,    401,  396, 

397 

tragicus,  529,  527 
transversal  is  colli,  400,  396, 

397 

transversiis  auris,  529,  527 
trape/.ius,  372.  65,  373 
triceps,  188,  65,  70,  76,  77, 
110,  184,  185,  381,  390 
tripartite,  388 

zygomaticus  major.  500,  491 

minor,  501,  491  , 

M  uscles  forming  thenar  eminence, 

171 
interossei.  dorsal,  211,  169, 

173,  206 
palmar,  187,  173 
interspinales,  404 
intertrausversales,  407 
intrinsic,  of  pinna,  527 
levatores  costarnm,  404,  397 
lunibricales,   168,  140,  159, 

169,  173 
of  arm,  114.  185 
of  back,  373,  396,  397 
of  ear,  469,  529 
of  eyebrows.  494 
of  eyelids,  494 
of  face,  490,  477,  491 
of  forearm,  130,  131,  194 


Muscles  of  mouth,  498 
of  nose,  490 
of  scalp.  477,  491 
of  scapula,  back,  185,  393 
rotatorcs  spime,  404 
Muscular  branch  of  hrachial  a.. 

Ill 

of  facial  a.,  5(17 
of   interosseous   a.,    208, 

309 

of  median  n..   1  I- 
of  princeps    cervicis  a., 

403 

Musculo-cutaneous    n.,    91,    123, 
126.     76,     87,     100, 
115,    118,   128,  131 
branches,  123 
course,  38 
motor  point,  40 
posterior  branch,  195 
relations,  123 

Musculo-spiral  n.,  91, 124, 192.76, 
77,    87,    110,    135, 
140,  141,   184,  200 
blanches.  125 


cutaneous  branch,  exter- 
nal, 100 
inferior,  96 
supe  rior, 

96 
internal,      103, 

188,  97 
incision  to  expose,    41, 

94 

irritation,  314 
motor  points,  40 
operation      to      expose, 
aboveelbow,  345,347 
paralvsis.  125 
relations,  125,  316,  317 
stretching,  313 

structures  involved, 

313 
Mylo-hyoid    a.,   547,   542,    546, 

550,  559 

nerve,  555,  542,  550,  559 
branches,  559 
incisive  branch,  555 
mental  branch,  555 


N. 

Nares,  anterior.   458 
Nasal  a.,  lateral,  477,  546,  559 
branch    of    infra-orbital    n., 

539,  561,  484 
of  Meckel's  ganglion,  562 
columna,  458 
duct,  458 
nerve,  539,  561,   473,  484, 

554,  559 

external  branch,  540 
naso-labial   branch,   493 
of    Meckel's    ganglion, 

562 

superior,  562,  554 
nerves,  inferior,  554 
septum,  578 

Naso-labial  branch  of  nasal  n.,  493 
Naso-palatine  a.,  54*,  554 


Naso-palatine  branch  of  Meckel's 

ganglion.  562 

Neck,  anatomic,  of  humerus,  273 
fracture,  273 

displacement, 

273 

structures      in- 
volved, 27:! 

of  scapula,  fracture.  270 
structures      in- 
volved, 270 
back,  351 

landmarks.  351 
incision  for  dissection,  487 
landmarks,  ,">51 
of  radius,  fracture,  277 
surgical,    of    humerus,    frac- 
ture, 273 
displacem  en  t. 

273,  272 
structures      in- 
involved.  •>?:! 
of  scapula,  fracture,  270 
veins,  509 
Nerve,  abducent.  592 

anterior  auricular.  552 
cutaneous,  52 
superior      dental,     561, 

559 

temporal,  542,  550 
auditory,  593 
auricular,  anterior,  .">.">•> 
great,  473 
posterior,  476,  530 
auriculo-temporal,   476,  552, 
473.  477,  484,  542, 
550,  554,  559 
divisions.  552 
buccal.  533,  473,  477,  484, 

542,  559 
long,   552,  550 
cervical,  eighth,  87 

posterior     division, 

410 
fifth,  87 

posterior      division, 

410 
first,    posterior  primary 

division.  409 
fourth,  87 

posterior     division, 

410 
second,  posteriorprimary 

division,  409 
seventh,  87 

posterior     division, 

410 
sixth,  87 

posterior     division, 

410 
third,  posterior  division, 

410 

cervico-facial,  533 
branches,  533 
chorda  tympani,     555,    542, 

550,  559 
circumflex.  124,  380,  76,  77, 

87,  184,  185,  381 
branches,  90,  124 
cutaneous  branch,  97 
irritation,  314 
motor  point,  41 
operation  to  expose,  341 


622 


INDEX. 


Nerve,  circumflex,  stretching.  3iMi 
structures  involved, 

306 

trauma.  1:21 
collateral  digital,  156 
cranial,  579 
cutaneous,  anterior.  52 

branch,  dorsal,  of  ulnar, 
l.r>l.  196,  97, 140, 
141 

external,  of  mus- 
cnlo-spiral,  97, 
100 

interior  external, 

of     mnscnlo- 

s].iral,       188, 

195 

of  nmsculo-spi- 

ral,  96 

internal,  ofmu-M-ulo 
spiral,  103,  188, 
77 

of  circumflex,  97 
of  median,  1:211 
of  ulnar,  126,  1.11 
palmar,  of  median, 

1 18.  97 
of    radial,    196, 

97 

of  nlnar,151, 97 
superlicial,  of  mus- 

culo-spiral,  96 
external,   126 
course.  :'," 

internal,     91,    96,    131, 
76,   77,   87,   97, 
100,  110,  128 
branches,  124,  97 
course,  38 
lateral,  52 

lesser  internal,  103,  188, 
195,  76,  77,  97,  110 
of  arm,  97 
of  back,  371,  369 
of  forearm,  97 
of  front  of  arm,  96 
palmar,  1.12 
deep  temporal,  .1.11 
dental,  anterior  superior,  561, 

559 
inferior,  555,  542,  550, 

559 
middle     superior,      558, 

559 
posterior    superior,   558, 

542,  550,  559 
digastric,  533 
digital,  167,  97,  159 
collateral,  156,  159 
I'acinian  bodies  on,  167 
relations,  167 
eighth  cranial.  593.  579 
eleventh  cranial,  593,  579 
external     anterior    thoracic, 

70.  71 
cutaneous.  :N 
palatine,  554 
respiratory,  of  Bell,79, 92 
superlicial  petrosal,  597 
facial,  .130,  59:2.  484,  485 
branches,  530 
bneeal  branch,  533,  473, 
477,  484 


Nerve,  facial,  course,  530 

digastric  branch.  533 
division  of,  facial,  530 
intra cranial,  530 
temporal.  r>.",D 
infra-maxillary    branch, 

531.  484 
infra-orbital  branch.  .133. 

473,  477,  484 
malar  branch.  533.  473, 

477,  484 

operation  to  expose,  539 
paralysis,  531 
stylo-hyoid  branch.    5.",.'! 
supra- maxillarv  branch, 

534,  473,  477,  484 
temporal    branch,      17ii. 

473,  477,  484 
fifth  cranial,   539.  592.  559, 

579 

branches,  539 
lirst  cranial,  591 
fourth  cranial.  592.  579 
glosso-pharyngeal,  593 
gustatory.  552 
hypoglossal,  593 
incisive     branch     of     mylo- 

hyoid.  .15.1,  559 
inferior     dental,    555,    542, 

550,  559 
maxillary.       551,      591. 

550,  559,  579 
branches,  551 
divisions,  551 
neurectomy,     intra- 

craiiial,  594 
nasal,  554 
infra-maxillary      branch     of 

cervico-l'acial.  534.  484 
infra-orbital,  539,  559 

branch  of  superior  max- 
illary. 539,   561,  473, 
484.  559 
branches,  539,  561,  473, 

484,  559 
labial,  539,  484 
nasal,  539,  484 
palpebral,  539,  484 
operation  to  exjiose,  563 
structures      in- 
volved, 563 
infra-trochlear,     473,     477, 

484 

intercostal,  first,  87 
intcrcosto-hnmeral,    91,   188, 

59,  76,  77,  97 
internal    cutaneous,  91,    96, 
124,   76,  77,   87, 
97,      100,     110, 
128 

branches,  121,  97 
course,  38 

interosseous,  anterior,  148 
posterior,       209,       135, 
140,    141,    200, 
203 

branches.  209 
relations,  209 
iutra-cranial,  591 

course.  .191 

labial,  539,  561,  484,  559 
lacrymal,  539 
lateral  cutaneous,  52 


Nerve,  lesser  internal   cutaneous, 
103.   iss,  U),l,  76,  77,  97, 
110 
lingual.  552.  542,  550,  559 

brandies.  .1,12 
long  buecal,  5.1:2 
lower      Mibscapular,      motor 

point,  40 
lumbar,  origin,  361 

posterior  division,  410 
malar  branch  of  facial,   533, 
.lid.     473,     477, 
484 

of  orbital.  558 
masseteric,  551,  485,  542 
maxillary,  inferior,  551,  591. 

550,  559,  579 
branches,  551 
neurectomy,     intra- 
cranial,  594 
structures  in- 
volved, 591 
superior,   557,   562.   .191, 

542,  550,  579 
branches.  .1.1-' 
course.    5.17 
infra-orbital  branch, 

473 

neurectomy,     intra- 
eranial.  .194 
structures  in- 
volved, 594 

median.  91, 123, 148, 162.  76, 
77,  87,  110,  115, 
118,  128,  131,  135, 
159 

branches,  123,  148,  1(32 
course.  :;> 

cutaneous  branch,  129 

palmar,  97 
divisions.  Ki2 
heads.   123 
incision    for    stretching, 

301 

irritation.  314 
line.  122,  300 
motor  points.  40 
operation  to  expose.  316, 

317,  319 
above     wrist, 

349 
relations.  123.  1  Is,  316, 

317 

at  elbow.  328,  329 
stretching.  312,  313 

structures  involved, 

312,  313 

mental.  540.  473,  484,  550 
middle  superior  dental.  5.1<. 

559 

motor  oculi.  579 
musculo  cutaneous.    91.    123. 
126.  76,  77,87,  100, 
115,  118,  128,    131 
branches.  123 
course.  3- 
motor  points,  40 
posterior  branch,  195 
relations.  123 

musculo-spiral.  91.    124,  192, 
76.77,87,  110,  135, 
140',  141,  184,  200 
branches,  125 


L\DI'X. 


623 


Nerve,  musculo-spiral.  course.  .'!- 

cutaneous      branch, 

external,  1OO 

inferior      c\tcr- 

nal,   96,    188, 

1!).") 

internal,     103, 

188,  97 
superior,  96 
incision    to   expose,   41, 

94 

irritation,  317 
motor  ]ioiiits,  40 
operation       to       expose, 

345,  347 
paralysis,  125 
relations,  125,  316,  317 
stretching,  313 

structures  involved, 

313 
mylo-hyoicl,   555,   542,  550, 

559 

brandies,  ,V>r>,  559 

incisive  branch,  555 

mental  branch,  555 

nasal,   539,    561.   473,   484, 

554,  559 

external  branch,  540 
inferior,  554 
naso-labial  branch,  493 
of     Meckel's    ganglion, 

562 

superior,  562,  554 
naso-labial    branch  of  uasal, 

493 

naso-palatine,  562,  554 
ninth  cranial,  593,  579 
occipital,     great,     368,     409, 
476,   373,   406,  473, 
477 

small,  476,  473,  477 
smallest,  410,  406 
third,  368 
occipitalis  major,  476 

minor,  47(3 
oculomotor,  591 
olfactory,  591,  554 
ophthalmic,  559,  579 
optic,  591,   579 
orbital,   558,  542,  550,  559 
of     Meckel's     ganglion, 

561 
temporal     branch,     476, 

473,  477,  484 
palatine,  anterior,  561 
external,  562,  554 
great,  554 
posterior,  562,  554 
palpebral,     539,    561,    484, 

559 

pathetic,  592 
petrosal,  superficial  external, 

5!)7 

large,  5!  16 
small,  51)6 

pharyngeal,  562,  554 
phrenic,  87 
pneiimogastric,  593 
posterior  auricular,  476,  530 
interosseous,  motor  point, 

41 

superior      dental,     558, 
542,  550,  559 


Nerve,  posterior  temporal,   542, 

550 

ptervgo-palatine,  562 
radial,    151,    196,    97,    131, 

135,  140,  141 
branches,  151,  100 
course.  3* 
cutaneous    branch.    196. 

97 
incision    for   stretching. 

301 

relations,  151.  328,  331 
stretching,  313 

structures  involved, 

313 
ramus     subeutaneus    mala;, 

558 

rhomboid,  87 
sacral,  origin.  :'.61 

posterior  division,  411 
second  cranial.  .">!ll 
sensory,     of    parotid   gland, 

521 
septal,  of  Meckel's  ganglion, 

562 
snpra-maxillarv     branch     of 

facial.  534,  484 
supra-orbital,  475,  473,  477, 

484 

neurectomy.  475 
supra-scapular,  384,  76,  87 
supra-sternal,  53 
supra-trochlcar,     475,     473, 

477 

neurectomy.  475 
temporal,   anterior,  476,  550 
branch    of    facial,    476, 
533,     473,     477, 
484 
of  orbital,  476,  558, 

473,  477 
posterior,  476,  542 
superficial,  552 
temjioro-facial,  533 
branches,  533 
temporo-malar,  558 
tenth,  593,  579 
third,  591 
thoracic,     external    anterior, 

90,  76,  87 
internal  anterior,  90,  76, 

87 
posterior  or  long,  92,  76, 

77,  87 

to  stibclavius  m.,  87 
tract,  cerebellar,  443 
Gowers',  443 
of  spinal  cord,  443,  441 
posterior,  444 
pyramidal,  443 
anterior,  443 
lateral,  44:; 
trifacial,  539,  592 
branches,  539 
twelfth,  5!)3,  579 
ulnar,  91,  123,  151.  162,  76, 
77,     87,     110,    115, 
118,  128,   131,  136, 
140,  141,  159,  173, 
185.  194,  200,  381 
branches.  151.  162 

course.  ::-• 

cutaneous  branch,  126 


Nerve,  uluar,   cutaneous  branch. 

dorsal.       1!Mi. 

97,140,141 

palmar,  97 

incision    for    stretching. 

301 

irritation,  314 
line,  312,  122,  300 
motor  point,  40 
operation  in  expose,  316, 

317 

relations,   123.   151,  162, 
316,  317,  321,  328, 
335 
stretching.  312,  313 

structures  involved, 

312,  313 
trauma,  123 
vagus,  593 

Vidiau,  562,  554,  559 
Nerves  at  elbow,  128 
cervical,  origin,  361 
deep  temporal,  551 
injury  following  fracture,  274 
of  arm,  120 

course.  •;" 
of  back,  367,  409 
of  face,  530,  473.  477,  484 
of  tbrearm,   195 
of  pectoral  region,  53 
of  ptervgo-maxillary  region, 

551 

of  scalp,  475,  473,  477 
of  upper  extremity,   stretch- 
ing, 311 

of  Wrisberg,  91,  103,  124 
origins  of  spinal,  351 
plexus  of,  axillary,  89,   76, 

87 

branches,  90 
formation,  89 
incision  for  stretch- 
ing, 301 
motor  points,  40 
pressure  upon,  89 
relations,  89 

to      snbclavian 

artery,  89 
stretching,  38,    311, 

314 

structures      in- 
volved, 312 
basilar,  579 
brachial.      J'iile  Axillary 

Nerve, 
cervical,     posterior,     of 

Cruveilhier,  409 
infra-orbital,   533,  539 
section,  38 
si  retching,  38 
thoracic,    posterior    primary 

division,  410 
to  levator  anguli  scapula;  m., 

87 

to  longus  colli  m.,  87 
to  sealeni  m.,  86 
Nervi  molles,  508 
Neuralgia,  trifacial,  562,  564 
Neurectomy,  intra-crauial,  of  in- 
ferior   maxillary    n., 
594 

of  superior  maxillarv  u., 
594 


624 


INDEX. 


Nenrectoniv   i)l'  supra-orbital    n.. 
17  :>  ' 

of  supra-tvochlcar  n.,  475 
Xinth  u.,  5!).'!,  579 
Nipple,  51,  55 

areola,  5-1,  55 

eczema.  57 

retraction,  5- 

structure,  51 

.supernumerary,  63 
Xose.    l.'i- 

Nose-bleed,   507 

Nourishment  of  Ion;;  holies.  '.Mil 

N'ucliiil  furrow.  :!51 

Nutrient  a.  of  luimerus,  11-1,  111 


O. 

Oblique  ligament  of  forearm.  1  I.'!. 

234'.  145,  225 
muscle,  external.  373,  396 
inferior,  496 
internal,  373,  396 
superior,  pulley  for.  496 
oceipilo-atliintal       ligament, 

417 
Obliquns  aiiris  in.,  529,  527 

eapitis     iuferioris     in.,     -Kw. 

397,  406 
action,  -1(1!) 
blood      supplv, 

403 

insertion,  408 
nerve      supply, 

409 

origin.    10* 
relations.    KIM 
superioris  in.,  408.  396, 

397,  406 
action,  408 
blood     supplv, 

403 

insertion,  10- 
nerve      supply, 

408 

origin,  408 
relations,  408 
Occipital  a..  402,  470,  406,  467, 

472,  477,  504 
anastomosis,  -170 
brandies.  402 
diploic  v.,  571,  569 
foramen,  superior,  582 
lymphatic  glands,  566 
Ivmpliatics,  476 
nerve,   great,    308,  409,   476, 
373,  406,  473,   477 
small,  476.  473,  477 
smallest,  410,  406 
third,  368 

protuberance,  external,  455 
sinus.  588,  579 
vein,  50!) 

Occipitalis  major  n..  476 
minor  n..   176 
muscle,  47!t.      Vide  Occipito- 

frontalis  Muscle. 
Occipito-atlantal  .joint,  423 
blood  supplv.  424 
ligaments,  415.  42:!.  417 
movements,  423' 
nerve  supply,  424 


Occipito-atlantal  ligaments.  415 
anterior.  -12:!.  417 
capsnlar.  417 
lateral.  42::.  417 
posterior.  423.  406,417 
Occipito-axoid     joint,    ligaments, 

120 

ligaments.    1211 

Oeei|iiti)-cer\  ienl  ligament,  420 
Occipito-  frontalis       aponeurosis, 

479,   463,  491 
muscle.    17!) 

action,  47!) 
aponcurosis,    479,    463, 

491 

blood  supply.  17!l 
insertion.  179 
uenc  supply,  47!) 
origin,    4711 
relations,  47!) 
Occipito-odontokl   ligament,   420, 

421 

lateral,  42:'>,  421 
Oculo-motor  n.,  51)1 
Odontoid  ligament,  420 
(  Hccrauon  process.  2* 
bursa,  188 
fracture.  27-' 

displacement.  27- 
structures  involved, 

278 
olfactory  n..  51)1,  554 

tract.  554 
Olixan   body.  439 
Omo-hyoid  in.,  378,  65 
Operation  for  harelip,  508 

hemorrhage  in,  508 
for     removal     of    (iasserian 
ganglion,  5!  15 
structures      in- 
volved, 5115 
of  parotid  gland,  522 
for  trifacial   neuralgia,  563 
on  mastoid  process,  5-7 
to  expose   axillary   a..   316, 

317 
brachial   a.,  316,    317, 

319 
circumflex  a..  341 

nerve,  341 
facial  n.,  539 
infra-orbital  n..  563 
median    n.,    316,    317, 

319 
above      w  r  i  s  t, 

349 
musculo-spiral   n.,  345, 

347 
posterior   circumflex   a., 

341 
radial    a.,    in    snuff-box, 

339 
subscapular  a..  343 

nerve,  343 
nlnar  n.,  316,  317 
Ophthalmic  a.,  579 

nerve,  559,  579 
Opponens  minimi  digiti  m..  179, 

141,  173 
action,  179 
blood      supplv, 

17!) 
insertion,  179 


Opponens  minimi  digit!  m..  ner\  c 

supply.  179 
origin.   1711 
relations.   17!l 
pollicis  m..   171,  140,   141, 

159 

action,  171 
blood  supply.   171 
insertion,  171 
nerve  supply,  171 
origin,  171 
relations,  171 
Optic  n.,  591,  579 
Orbicular  ligament,  233,  225 
Orbieularis  oculi  in.      ]'idi  Orbic- 
ularisl'alpchrarum  Muscle, 
oris  m.,  4!)s,  491 
action,  4!)!l 
nerve  supply,  499 
relations.  499 
palpebrarum  m..  4!)4,  491 
action,    197 
insertion.  4!>7 
nerve  supply.  -I!I7 
origin,   494 
relations,  494 

Orbital  a.,  472,  477,  504.  546 
branch  of  MeckePs  ganglion, 

561 
of  superior  maxillary  n., 

558 

fat,  496 
nerve.  542,  550,  559 

temporal     branch,     476, 

473,  477,  484 
vein,  509 

Orbito-tarsal  ligament.  516 
Orifice    of    duct    of    Mcihomiau 

gland.  517 

of  laciymal  duct.  517 
Ossification  centers  of  carpus.  2(19 
of  claxide.  260 
of  humerus,  266 
of  metacarpus,  269 
of  phalanges.  269 
of  radius.  2ii6 
of  scapula,  266 
of  ulna,  26!) 
Osteoblasts.  259 
Osteo-fascial      compartments     of 

arm.    Ids 
contents,  108 

Ostco-librous  canal  of  hand.  167 
( Isteo-genctic  layer  of  periosteum, 

259 

Othematomata,  524 
Otic  ganglion.  555.  554 
Oval  method  of  amputation,  283 


P. 

Pacchionian  bodies,  572,  573 
I'aciniau  bodies  of  digital  n.,  167 
I'aget's  disease.  57 
Palatine  a.,  5-18.  546 

nerve,  anterior.   561,  562 
external.  554 
great.  554 
posterior,  562.  554 
Palm.  32 

dissection,  152 

lines  for  arteries,  176 


IXDKX. 


Palm.  skin.  152 
triangle,  :i2 
1'iiliiiiir  arch,  course,  37 

deep.     17!),     145,    173, 

177 

branches.  1-0 
{•nurse,  l-i> 
line,      122,      176, 

300 

relations,  180 
superlieial.       147,       161, 
145,    159,  177, 
300 

branches,  161 
course,  161 
formation,  161 
line,  122,  176 
relations,  161 
wounds,  180 
bursa,  157 

abscess,  158 
cutaneous  branch  of  median 

n.,  1)8,  97 
of  radial  n.,  196,  97 
nfulnar  n.,  151,  97 
nerve,  15:2 
fascia,  deep,  158,  156 

abscess,  158 
dividing  Hue,  37 
stiperlicial,  153 
furrow,  37,  34 
mterosseous    a.,    180,    145, 

177 

anastomosis,  180 
course,  180 
ligament  of  carpal  joint,  238, 

241 
of        carpo  -  metacarpal 

joint,   242 
of  intermetacarpal  joint, 

•245 

Palmaris  brevis  m.,  152,  156 
insertion,  152 
nerve  supply,  152 
origin,   152 
lougus   m.,   133,   110,    128, 

131,  135 
action,  134 
blood  supply,  133 
insertion,  133 
nerve  supply,  134 
origin,  133 
relations,  133 
tendon,  135,  159 
Palpebrae,  512 
Palpebral  a.,  546 

branch    of    infra-orbital    n., 

539,  561,  484,  559 
commissures,   512 
fascia,  516 
fissure,  457,  513 
ligaments,  516 
portion  of  conjunctiva,  515 
Palsy,  Bell's,  534 
Pannicnlus  carnosus  m.,  48 
Papilla;  lachrymalue,  512 
Paralysis  of  facial  n.,  534 
of  musculo-spiral  n.,  125 
of  serratus  magnns  in.,  79 
Parietal  eminences,  456 
Parotid  abscess,  521 

incision,  522 
fascia,  520 
40 


Parotid    gland.    5:20,    472,    477, 
491,  504 

contents,  521 
lobe  of.   carotid,  520 
' 


pterygoid.  52O 
relations. 
removal,  522 
sensory      nerve     supply, 

52) 

wounds,  522 

lymphatic  glands,  5:21,  566 
Pathetic  n.,  592 
Pectoral  fascia,  63,  59 
deep,  67 
diagram.  62 
region,  abscess,  68 
1  dissection,  48 

nerves,  .">:! 

superlieial   fascia,  49 
Pectoralis  major  in.,  63,  52,  62, 
65,  70,  71,    76, 
77,  110 
action,  64 
blood  supply,  67 
in       carcinoma      of 

breast,    67 
insertion,  64 
nerve  supply,  G7 
origin,  63 
relations,  64 
sheath,  63 
tendon,  115,  118 
minor  m.,  73,  62,  65,  76 
action,  74 
blood  supply,  74 
insertion,  73 
nerve  supply,  71 
origin,  73 
relations,  74 
tendon,  118 
Percussion  of  chest,  352 
Perforating  a.  of  hand,  180,  173, 

177 

anastomosis,  180 
course,  180 
branch,  anterior,  of  intcrossei 

a.,  211 
of  internal  mammary  a., 

48,  49 

Pericranium,  481,  463 
Periosteum,  259 

inflammation,  260 
of  spinal  canal,  428 
osteo-genetic  layer,  259 
Periostitis,  260 
PCS  anserinus,  534 
Petit,  triangle,  376,  52,  373 
Petrosal  n.,  superficial  external, 

507 

large,  596 

small,  596 

sinus,     inferior,    590,     578, 

579 

superior,  590,  579 
Phalangeal  joint,  17 
Phalanges,  amputation,  283 

structures  involved,  283 
development,  269 
dislocation,  256 

structures  involved,  256 
excision,  265 

structures  involved,  265 


Phalanges,  fracture,  179 

displacement  in,  -27!) 
Phalanx,  centers  of  ossification  of 

each,  269 

Pharyngcal  n.,  562,  554 
Phlegmonous  erysipelas.    1-0 
Phrenic  n.,  87 
Pia    mater   of   spinal   cord,   432, 

429 

Pingnecuke,  516 
Pinna.    165,  524,  5'2!l.  525 
action.   5:2!) 
blood  supply,  529 
cartilage,  5:29 
intrinsic  muscles,  527 
lymphatics.  529 
iierve  supply,  529 
skin,  5:24 

Pisitbrm  bone  of  carpus,  31 
Piso-metacarpal  ligament,  241 
Piso-imcinate  ligament,  241 
Pituitary  body,  579 

t'ossa,  diaphragm,  5s  1 
Platysma  myokles  m.,  485,  491 

origin,  48 

Pleural  sac,  aspiration,  351 
Plexus   of    nerves,    axillary,    89, 

76,  87 
branches,  90 
formation,  89 
incision  for  stretch- 
ing, 301 
motor  points,  40 
pressure  upon,  89 
relations,  89 
stretching,   38,   311. 

314 

structures      in- 
volved, 312 
basilar,  579 
brachial.    Vide  Axillary, 
cervical,     posterior,     of 

Cruveilhier,  409 
infra-orbital,  533,  539 
of  veins,  pterygoid,  551 
parotidens,  534 
Plica  semilunaris.  515,  513 
Pneumogastric  n.,  593 
Pneumonia,  lobar,  diagnosis,  352 
Polymastia,  63 
Polymazia,  63 
Polythelia,  63 
Pons  Varolii,  439 
Pre-carpal  arch,  148 
Preservation  of  brain,  581 
Pressure  method  of  treating  aneu- 

rysm,  297 
upon  axillary  a.,  81 

plexus  of  nerves,  89 
vein,  81 

Princeps  cervicis  a.,  402,  406 
anastomosis,  402 
branches,  402 

pollicis  a.,  180,  140,  141, 
145,  159,  173, 
177 

branches.  180 
course,  180 
line,  176 
relations,  180 
Process,  acromion,  18,  43 
epiphyses,  18 

u'nunited,  266 


626 


INDEX. 


1'roress,    aeromion.    fracture,    18, 

270 
coracoid.  18,  43,  115 

'l~0 
coronoid,    ol'   ulna,    1'racture, 

278 
cl  is  placement, 

278 

structures      in- 
volved, 278 
mastciid.    I.V, 

uperations  upon.  5-7 
oleorauon,  28 
fracture,  :>7- 

displacement,  278 
structures  involved. 

278 

styloid,  of  radius,  l!l 
supra-condyloid,  •_'- 
Processes  of  dura  mater  of  brain, 

581,  578 

Processiis  camlatiis,  527 
Profunda  a.,   inferior,   113    110. 
Ill,    115,    118, 
128,  145 
anastomosis,  114 
superior.    113,  102.  110, 
111,    145,    184, 
194,  200 
anastomosis,     113, 

192 

brandies,  113,  192 
relations,  102 
cvrvicisa.,  403,  406 

anastomoMs.  403 
1'ronatorquadratus  m..  138,  135, 

140,  141 
ail  ion,  143 
blood  supply,  138 
insertion,   13* 
nerve  supply,  138 
origin,  13-< ' 
relations,    13- 

radii  teresm.,  130, 118,  128, 

131,        135, 

140,       141 

action,  133 

blood     supply, 

133 

head,  coronoid, 
140,141 
deep,  130 
superficial, 

130 

insertion,  130 
nerve      supply, 

133 

origin.   130 
relations,  130 

Protection  1o  spinal  cord,  449 
Protuberance,  external  occipital, 

455 

I'soas  abscess.  35(i 
Pterion,  452 
Pterygoid  a..  547,  542 

external,  548,  546 
internal,  548,  546 
lobe  of  parotid  gland,  520 
muscle,  external  543,  542 
action,  544 
blood  supply.  544 
insertion,  543 
nerve  supply,  544 


Pterygoid    muscle,    external,    mi 

gin,   543 
relations,  544 
internal,  541.  542,550. 

554 

action,  5  1 1 
blood  supply,  544 
insertion,  544 
nerve  supply,  51  I 
origin,  5-1  1 
relations,  544 
plexus  of  veins,  551 
Pterygo-maxillary  ligament.   501 
region,  540,  542 

abscess,   556' 

contents.   513 
dissection.  ~>  Id 
hemorrhage  into.  55fi 
lymphatics,  551 
nerves.  551 
veins.  551 

Pterygo-palatine  a.,  548.  546 
Ibraincn.  557 
nerve.  5l!2 
Pulley   for   superior  oblique  in., 

496 
Pulsations  of  dura  mate]'  of  brain, 

575 

of  radial  a.,  32 
Pulse,  32 

absence,  81 
double,  32,  144 
Pulsus  duplex,  32 
I'nneta    lacbrymalia,    458,     51-;. 

496,  513  ' 
Pyramid,  anterior,  439 
Pyramidal    nerve   tract,  anterior. 

I  13 

lateral,  413 

Pyramidalis  nasi  in.,  490,  491 
action,  493 
insertion,  490 
nerve  supply,  493 
origin,  490 
relations,  490 


Q 

Quadratns  ineuti  in.,  500.  F'/Vc 
Depressor  Labii  Inferioris  Mus- 
cle. 


R. 

Radial  a.,  143,  210,  110,  111, 
128,  131,  135,  140, 
141,  145,  159,  173, 
177,  194,  200,  206 

branches,  144,  210 
course,  31 

incision  for  ligating,  301 
ill  snuff-box,  339 

line  of  incision,  337 
ligation.  310 

collateral       circula- 
tion,  311 
structures  involved. 

310 
line.  143,  309,  122,  176, 

300 
pulsation.  32 


Radial  a.,  recurrent.  144.  145 
anastomosis.   Ill 
relations.   1  13.  -.'10.  328. 

331,  333 
to  bieipital   aponeii- 

rosis.  1111 
vena  comes.  128 
head  of  llexor  sublimis  digi- 

torum  m.,    13  I 
nerve,    151.    19(i,    97,    131, 

135.  140,  141 
brain-lies.  151.  100 
course.  3* 
cutaneous    branch,     1'lii. 

97 
incision    for    stretching. 

301 

relations,  151.  328,  331 
stretching,  313 

structures  involved. 

313 
pulse.  32 

absence.  81 
double,  32,  144 
recurrent  a.,  144,  131,  135, 
140,    141,    345, 
347 

anastomosis.  141 
vein.    12fi.     195,    100,    101, 

128,  339 

Radialis  indicia  a.,  180, 140, 141, 
145,  159,  173, 
177 

course,  180 
line,   170 
Radio-carpal  joint.  17,  234,  231. 

235,  239 
blood  supply,  " 
disarticulation,  :.'.- 1 

structures  involved, 

287 
dislocation,  255 

structures  involved, 

255 
excision.  263 

structures  involved, 

264 

formation,  234 
ligaments,  234 
movements,  17,  238 
nerve  supply,  238 
ligaments,  anterior,  237,  230, 

235 

external,  237 
posterior,  237,  231 
Kadio-ulnar   joint,    inferior,    17, 

233,  230 
blood  supply,  234 
formation,  233 
ligaments,  233 
movements,  233 
nerve  supply,  234 
superior,  17,  233 

blood  supply,  233 
formation,  233 
ligaments,  233 
movements,  233 
nerve  supply,  233 
synovitis,  237 
ligaments.       anterior,       233, 

230,  235 
posterior,  233,  231 
Radius,  31,  200 


INDEX. 


627 


K:ulius  and  ulna.  fracture.  27- 

structures  involved. 
278 

centers  of  os-iliration,    2H(> 

ilevelopinrnt,   2(i(i 
dislocation,  252,  25  I 

structures  involved,  253, 

25  1 
excision.  263 

structures   involved,  263 
fracture,  277 

displacement.   277.   276 
stnictnrcs  involved.  277 
position  of  head,  2S,  25 
tuberosity.  2* 

Rainn.s  subciituncus  mala-  n.,  558 
Rectus  capitis  posticns  major  m., 
•108,      397, 
406 

action,  408 
blood      supply, 

403 

insertion,  408 
nerve      supply. 

408 

origin,  408 
relations,  40* 
minor  in.,  408,  397, 

406 

action,  408 
blood      supply, 

103 

insertion,  408 
nerve      supply, 

408 

origin,  408 
relations,  408 
muscle,  inferior,  496 

superior,  496 
sternalis  in.,  (>  I 
li'ccnrrent    a.,    carpal.    1*0,  145, 

173,  177 
anastomosis.  180 
course.   I -i  i 
interosscoiis,  208.  145 

posterior,  111,  200 
radial,    Ml,   131,   135, 
140,    141,   345, 
347 

anastomosis.  144 
ulnar,       anterior,       147, 
111,        140, 
141,  145 
a  nastomosis. 

1  17 

posterior,  147,  111, 
140,       141, 
145,  200 
anastomosis, 

147 
Reflected  portion  of  conjunctiva, 

.">  1 5 
Kellex  action,  445 

areas  of  spinal  cord,  445 
K'cid's  base  line,  453 
Removal  of  brain,  576 

of  Gasserian  ganglion,  595 
structures  involved, 

595 
Respiratory  n.,  external,  of  Bell, 

92 

1,'ctc.  acromial,  85 
Rctraheus  aurem  in.,  46!),  491 


liYtrahens  aurem  in.,  action,  469 
insertion,  4blt 
nerve  supply,   16<J 
origin.  -Kill 

Ketro-pharyngeal  abscess,  :!5(i 
Rhomboid  ligament,  21<>,  214 

relations,  216 
nerve,  87 

Rbomboidens  major  m..  377.  373 
action,   ill- 
blood  supply.  378 
insertion.  :'.77 
ncnc  supply,  377 
origin.   377 
n-lations.  377 
minor  m.,  377,  373 
action,   377 
blood  supply.  377 
insertion.  377 
nerve  supply,  377 
(infill.  i!77 
relations.  377 
Ridges,  superciliary.    152 

tcni]M>ral.    |.~>i; 
Kisorius  m.,  498,  491 
action,  498 
insertion,  498 
nerve  supply,  498 
origin.    In- 
Risus  sardonicus,  4!l-< 
Roots  of  spinal  nerves,   anterior, 

432 

posterior,  432 
Rotatores  spina'  m..  40  I 
aelion,    101 
blood  supply,  403 
insertion.   1(11 
nerve  supply,  404 
origin,  404 
relations,  404 
Roundness  of  shoulder,  18 
Rupture  of  biceps  in.,  130 


a. 

Sac,  laerymal,  458,  517 

abscess.  508 
plenral,  aspiration.  351 
Sacral  n.,  origin,  301 

posterior    primary   divi- 
sions. 411 
vertebra?,  361 
Saero-lmiibalism.,  399.    Vide  Ilio- 

costalis  Muscle. 
Sagittal  suture,  452 
Salivary  fistula,  522 
Santori'ni,  fissure,  530.  527 

muscle,  498.     Vide  Risorius 

Muscle. 
Sarcoma  of  clavicle,  361 

of  dura  mater  of  brain,  575 
of  tubercle  of  Montgomery, 

57 

Scaleni  m.,  nerve  to,  87 
Scalenns  posticns  m.,  396 
Scalp,  451,  465 
abscess,  481 
areolar  tissue,  480 
arteries,  452,  469,  472,  477, 

504 
congestion,  479 


Scalp,  dissection,    !((."> 
lascia,  -!•;(>,  467 
heinatoma.    1-1 
inflammation.  -1*1 
layers,  4(i5,  463 
lymphatics.    I7(i.  5(>7 
mobility,  -HO 
muscles.    177.  491 
nerves,  475,  473,  477 
skin,  46(i 
tumors,  451.  4*0 
veins.  470,  509 
wounds,  466.    1-0 
Scalping,  480 
Scaphoid  tbssa.  524 

tubercle,  .'!! 
Scapula.  351 

acroiniou  process  of,  fracture. 

270 
anastomosis     of     arteries 

around,  84,  385 
angle  of,  inferior,  :',<>'! 
back  of,  muscles,  185 
body  of,  fracture,  270 
centers  of  o»ilication.  2fiG 
coracoid  process  of,  fracture, 

270 

development,  266 
dislocation.  222 
dorsuni,  43 
fossa,  383 
fractures,  270 

struc'tures  involved.  270 
ligaments,  222 
movements,  367 
muscles  of,  attachment,  393 
position.  362 
spine.  IS,  43,  184 

fracture,  270 
winged,  222,  362 
Scapular   a.,   posterior.  384.    84, 

385 
a  n  ast  oin  os  is,  86, 

384,  385 
branches.  :;-  I 
origin.  3S4 
relations,  384 
Scapulo-clavienlar       joint,      221, 

218.  219 
blood  supply,  222 
formation,  221 
ligaments,  221 
movements.  222 
nerve  supply,  222 
relations,  222 
Scapnlo-hunicral    joint.        Vide 

Shoulder  joint. 
Sclerotic  portion  of  conjunctiva, 

515 

Sebaceous  gland  of  nipple,  54 
Second  cervical  n.,  posterior  prim- 
ary division,  409 
cranial  n.,  5!)1 
Section,  transverse,  of  arm,  290, 

291 

of  forearm,  286 
Sections  of  spinal  cord,  437 
Semilunar  lines  of  abdomen,  52 
Semispinalis  colli  m.,  403,  396, 

397,  406 
action,   404 
blood  supply,  403 
insertion,  403 


I.\J)EX. 


i.inalis     culli      m.,      nerve 

supply.    Hi:! 
origin.    In:; 

relations.  40:; 

dorsi   m.,    40:!.    396,     397, 
406 

action,    -lit:! 
blood  supply,  403 
insertion,   in:; 
nerve  supply,  403 
origin,  -103 
relations,    HI:; 

•i  v  arras  ot'  spinal   con!.  445 
impulse,  450 

course,   450 

nerves  of  parotid  gland,  521 
Septa,  intcrnuisrular,  ol'urni,  107 

orliitale,  510 
S.ptal  branch  of  Meckel's  gang- 

lion,  502 
Septic   matter,    entrance  of,   into 

veins,  81 
Septum,  intcnnnscular.  external, 

of  arm,  107 
internal,  of  arm,  107 
of  forearm,  129 
of   nose,   artery,    ',07,    477, 

504 
hemorrhage   fro  m, 

507 

Serratus  niagniis  m..  3*7.  52,  65, 
71,  76,  77,  373, 
391 

action,  388 
blood  supply,  388 
insertion.  3S8 
nerve  supply,  388 
origin,  387 
paralysis,  79 
relations,  388 
posticus    inferioris   m.,    394, 

373,  396 
action,  394 
insertion,  394 
nerve      supply, 

:;:M 

origin,  394 
relations,  391 
superioris  m.,  393,  373, 

396 

action,  394 
insertion,  393 
nerve      supply, 

393 

origin,  393 
relations.  393 

Sesanioid  bone  of  thumb,  .'!7,  :.' 17 
Seventh  cervical  nerves,  posterior 

division,  410 
cranial  n.,  592.  579 
Shaft  of  humerns,  fracture,  273 
displacement,     273, 

272 
structures  involved, 

273 
Sheath  of  arteries,  298 

of  axillary  vessels,  80 
of  flexor  tendons,  107,  166 
inflammation,  157 
of  pectoralis  major  m.,  63 
synovial,    of    flexor   tendons 

of  fingers,  37 
Shoulder,  362 


Shoulder,  back,  351 

landmarks,  351 
buliv  arch,  18 

cap,  378 

dislocation.  2 18,  29 
excision,  201 

structures   iiiMihed,  261 
landmarks,  351         • 
roundness,  18 

Shoulder-joint.  17,  222,  218 
abscess,  379 
amputation,  293 

structures  involved,  293 
blood  supply,  224 
bursa-.  223 
excision,  89 
formation,  222 
ligaments.  22:'. 
movements.  224 
nerve  supply,  224 
relations.  22  I 
synovial  membrane,  223 
synovitis,  223 
Sigruoid  sinus,  584,  579 

course,  456 
Sinus  a  he  paiva-,  688 

cavernous,  relation  to  (iasse- 

rian  ganglion.  589 
circular,  590,  578,  579 
frontal,  517,  569,  573 
inferior     longitudinal,     588, 

578 

petrosal,  590,  578,  579 
lateral,  584,  578,  579 
course,   150 
divisions,  584 
line,  587,  585 
thrombosis,  .">-  I 
tributaries,  584 
longitudinal,     inferior,     588, 

578 

superior,  583,  578,  579 
course,  450 
line,  583 
wound.  583 
occipital,  588,  579 
petrosal.   inferior,   590,   578, 

579 

superior.  ".90,  579 
sigmoid,  579 

course,  456 
sphcno-parictal,  588 
straight.  .>'s.  578 
superior    longitudinal,    583, 

578,  579 
course,  456 
line,  583 
wound,  583 
petrosal,  590,  579 
transverse,  590,   578,  579 
Sinuses,  cavernous,  589,  579 

of  dura  mater  of  brain.  5*2. 

578,  579 
hemorrhage 

from,  583 

of  frontal  bone,  455 
;    Sixth   cervical  n.,  posterior  divi- 
sion, 410 

cranial  n.,  592,  579 
Skeleton,  fetal,  skiagraph.  257 
Skiagraph  of  fetal  skeleton,  257 
,   Skin  of  face,  4S9 
of  palm,  152 


Skin  of  pinna,  524 

of  seal]..  400,  463 
Skull,  blood  supply.  -181 

fracture.  55(i,   f>7] 
Slit,  iuterpalpebr.il,  512 
Snoring,  501 
Snutl'-box.  anatomic,  32 
Socia    parotidis,   520,   522,    477, 

491 
Sjieiice's  method  of  amputation, 

282 

test,  58 

Sphenoidal  cells,  578 
Spheno-maxillary  division  of  in- 
ternal maxillary  a.,  547 
fossa,  557 

contents.   557 
foramina,  557 

Spheno-palatine  a.,  548,  546 
foramen,  557 
ganglion,  561 
nerve,  558,  554,  559 
Spheno-parietal  sinus,  588 
Sphincter  oculi  in.      Vide  Orbicu- 
laris  1'aJpcbrariim  .Muscle. 
oris   in.,   498.      Viile  Orbicu- 

laris  (iris  Muscle. 
Spina  bih'da,  431 
Spinal  accessory  n.,  593 
arteries,  427 
lateral,  444 
posterior,  444 
artery,   anterior,   444,    429, 

433 

median,  444 
canal,  periosteum,  428 
tumors,  449 
reins,  427 

column,  fracture,  449 
ligaments,  412,  413 
movements,     407,     416, 

419 
cord,  429,  439 

arachnoid,  431,  429 
areas  of,  motor,  445 
reflex,  445 
sensory,  445 
arteries,  444 
blood  supply,  427 
canal  of,  central,  436 

tumors,  449 
commissure  of,  gray,  436 

white,  436 
disease,  446 
dissection,  428 
dura  mater,  428,  429 
enlargement  of,  cervical, 

428 

lumbar,  428 
fissures,  435 
in  fetus,  428 
injuries  to.  449 
lesions,  446 
median  a.,  444 
membranes,  428,  429 
motor  tract  of,  degenera- 
tion in,  450 
nerve  tracts,  4  13.  441 
pia  mater,  432.  429 
protection  to,  449 
sections,  437 
structure    of,    macro- 
scopic, 436 


INDEX, 


629 


Spinal  cord,  veins,  445 
curvature,  352 
angular,  359 

lateral,   358 

iii.rnuil,  358,  359 
I'll  now,  351 
meningitis,    151 
nerves.  368 

intra-theeal  course,  435 
origin.  'M\ 
roots.    13'.' 
Spiualis  eolli  ra.,  401 

action.    lo] 
insei'tion,  101 
nerve  supply,  401 
origin,  401 
relations.   101 
dorei  m.,  401,  396,  397 
action,  401 
blood  supply,  401 
insertion,  401 
nerve  supply,  401 
origin,   401 
relations,  40l 
Spine,  cervical,  seventh,  361 

sixth,  356 
lumbar,    lirst.   second,    third, 

fourth,  fifth,  361 
of  scapula,  18,  43,  184 

fracture,  27o 
sacral,  third,  361 
Spines  of  vertebra1,  352,  356 
lumbar,  361 
sacral,  361 
thoracic,  361 
Spleen,  ]K)sition,  362 
Splenins  capitis  et  colli  in.,  3!M. 
J "/'(/<•  Splenins  Muscle, 
muscle,  373,  396 
colli  m.,  373,  396 
muscle,  394 

action,   394 
insertion.  394 
nerve  supply,  394 
origin,  394 
relations,  394 
Stenson's  duct,  522,  473,  477, 

485,  491,  504 
course,  522 
divisions,  523 
line,  487 
relations,  522 
Stephanion,  456 

Sterno-clavicular  joint,  215,  214 
blood  supply,  216 
formation,  215 
ligaments,  216,  214 

relations,  216 
movements,  221 
nerve  supply,  221 
Sterno-hvoid  m.,  65 
Stcnio-niastoid  m.,  65,  373 
Sterno-thyroid  m.,  65 
Stertorous  breathing,  501 
Straight  sinus,  588,  578 
Stretching    of     axillary    plexus 
of  nerves,  38, 
311,  314 
structures      in- 
volved, 312 
of  circumflex  n.,  312 
of  median  n.,  312,  313 
of  musculo-spiral  n.,  313 


Stretching  of  nerves  of  upper  ex- 

tremitv,  311 
of  radial  n.,  313 

of  nlnar  n..  312,  :!13 
Stylo-hvoid   brunch  of   facial   n. , 

Styloid  process  of  radius.  :!1 
Subacromial  bursu,  inflammation, 

223 

Subauconeus  in.,  192 
action.  192 
nerve  supply,  192 
Siibaruchnoid  sjiace  of  spinal  cord 

341 

Subclavian  a.,  relation  of,  to  ax- 
illary plexus  of  nerves,  89 
vein,  509 
Subclavicular  dislocation   of   1m 

nienis.   251 
structures  involved. 

251,  252 

Subclavius  m.,  68,  62,  71 
action,  73 
blood  supply,  73 
nerve  supply.  73,  87 
Subeoracoid    dislocation     of     hu- 

inerus.  251 
structures  involved, 

251,  252 

Subdeltoid  bnrsa,  379 
abscess.  379 
inllanimation,  379 
Subdural   space  of   spinal   cord, 

431 
Suhgleiioid     dislocation     of    liu- 

inerus.  •_'  l~ 
structures  involved, 

2K  252 

Snbmammary  cyst,  58 
Subma.xillarv  lymphatic   glands, 

566 
Submental  a..  546 

vein,  509 
Suboccipital     Ivmjihatic    glands, 

566 

nerve,    IDS,  40!).  406 
triangle,  407,  406 
contents,   4u7 
formation,    107 
Subscapular  aponeurosis,  387 

artery,   86,   66,   67,  76,  77, 

84,  111,  385 
anastomosis,  86,  385 
brandies,  86 
incision  for  ligating,  301 
ligatiou,  ::oii 

structures  involved. 

306 

line,  86 

operation  to  expose,  343 
nerve,  90 

lower,  76,  77,  87 
motor  point,  40 
operation  to  expose, 

343 
middle  or   long,  90,  76, 

77,  87 
motor       point, 

40 

operation  to  ex- 
pose, 343 
upper.  90.  87 
triangle,  86,  390 


Subscapular  vein,  343 
Snliscapularis  m.,    3*7,    62,    65, 
71,  76,  77,  343.  390 
action. 

blood  supply,  387 
insertion,  ."-" 
nerve  supply,  387 
origin,   387 
relations,  387 
Subspiuous     dislocation    of    bu- 

menis,   :>51 
structures  involved, 

251,  :.':••-' 
Snbstantia     gelatinosa     Kolaudi, 

436 

Sulcns,  delto-pectorul,  64 
Superciliary  ridges,  452 
Superlicialis     vohc     a.,     32,    144. 
131,    135,   145, 
159,  173,  177 
line.  176 
Supernumerary  mammary  gland, 

53,  <>:: 
nipple,  63 
Snpinator    brevis  in.,    202.    135, 

140,  141,  200 
action,  202 
blood  supply.  202 
insertion.  202 
nerve  supply,  202 
origin,  202 
relations,  202 

longus  m.,    197,  110,  115. 
118,    128,    131, 
135,   14O,    141 
184.   194,    200, 
345,  347 
action,  198 
blood  supply,  198 
insertion,  197 
nerve  supply,  198 
origin,   197 
relations,  197 
radii  brevis  m.,  202 
longus  m..  J97 
Snpra-acroniial  n.,  53,  97 
Supra-clavicular  n.,  53 
Supru-coiidyloid  foramen,  28 
fracture  of  humenis,  274 
process,  28 
Supra-maxillary  branch  of  facial 

n ..  534,473,  477,  484 
Supra-orbital  arches,  457 

artery,  469,  467,  472,  477, 

484,  504 
anastomosis,  469 
foramen,  459 
nerve,   175,  473,  477,  484 

neurectomy,  475 
notch,  459 
vein,  509 

Supra-scapular  a.,  384,  84,  385 
anastomosis,      85,     384, 

385 

relations.  384 
ligament,  222 
nerve,  384,  76,  87 
vein,  509 
Supra-spinatus     m.,    383,     184, 

186, 373,  381 
action,  384 
blood  supply,  384 
insertion,  383 


630 


Snpra-spinatns  in.,  nerve  supply. 
384 

origin.   3-3 
relations,  383 
Supra,  spinous  fascia.  3-3 

liniment,  -11.").  396,  413 
Supra-Menial   n.,  53 
Supra-lrorlilear     n.,     -175,     473, 

477 

neniectomy.  475 
Surface  markings  of  arm.  27.  21, 

24,  25 

of  auricle,  465 
nf  axilla.  27 
of  back,  353 
of  neck,  351 
of  shoulder.  352 
of  trunk,  35 1 
of  cranium,   451,  453 
of  ear,   565 
of  elbow,  28 
ol'  eve.    157 
of  face,  456 
of  forearm.  31 
of  band.  32 
of  knuckles,  37 
of  neck,  351 

of  back.  351 
of  pinna.  5(i5 
of  shoulder,  352 
of  back,  351 
of  trunk,  351 

of  back.  351 
of  upper  extremity,  17 
Surgical    neck   of  bumerns,  frac- 
ture, 273 
of  scapula,    fracture, 

270 

Suspensory    ligament     of    axilla, 
'  08 

of  mammary  gland,  54 
of  occipito-axoid   joint, 

420 

Suture,  coronal,  452 
frontal,  452 
lanibdokl,  452 
sagittal.  452 
Synovial  membrane,  215 

of    atlanto-axoiil    joint, 

419,  417 

of  carpal  joint.  2  11 
of   c  a  r  p  o  -  metacarpal 

joint,  245 
of  carpus,  242 
of  elbow,  228 
of  intermetacarpal  joint, 

216 
of  interphalangeal  joint, 

217 
of    niedio-earpal     joint, 

242 
of  metacarpo-phalangeal 

joint,  246 
of    radio-carpal     joint, 

ajn 

of      radio-ulnar      joint, 

233,  234 

of  shoulder-joint,  223 
Syuovitis  of  elbow,  '-'•-'- 

of  radio-carpal«joint,  237 
of  shoulder-joint,  223 
of  wrist,  237 


T. 

Tarsal  cartilage.  457,  516 
ligament,  external,  494 

internal,  494 
Tcale's    method    of    amputation, 

281 
Temporal  a.,  470 

anterior,  470,  467,  472, 

477, 504 
deep.      517,       546, 

542,   550 
middle,  472,  477,  484, 

504 
posterior.  470,  467,  472 

477,  504 
anastomosis.   170 
deep.  547,  542,  546 
superficial,     472,    477, 
484,  485,  504,  542. 
546,  550 
branch  of  facial  n.,  47(i,  533, 

473,  477,  484 
of  orbital  n.,  47(i,   568, 

473,  477,  484 
division  of  facial  n.,  530 
fascia,  482,  484 

abscess  beneath,  482 
density.  4*2 
relations,  482 
lymphatics,  479 
muscle,  48!),  485,  542,  550 
action,  489 
blood  supply,  489 
insertion.    l-'!i 
nerve  supply,  489 
origin,  489 

nerve,  anterior,  476.  550 
posterior,  476.  542 
superficial,  552 
nerves,  deep.  551 
region,  489,  485 
ridges.  456 
vein,  middle,  509 

superficial,     477,     484, 

509 

Teniporo-facial  n.,  533 
branches,  533 
Teuiporo-inalar  n.,  558 
Temporo-maxillar.v  v.,  485,  509 
Tenalgia  crepitans,  32,  197 
Tendons,  extensor,  209 
insertion,  210 
flexor.  167 

insertion,  168 
sheaths,  166 
theca.  166 
Tendo  oculi,  458,  494,  516 

palpebrarum.  494 
Teno-synovitis.  197 
Tensor  palati  in..  554 

tarsi  m.,  497,  496,  517 
action,   498 
insertion,  497 
nerve  supply,  498 
origin,  497 
relations,  497 
Tenth  n.,  593,  579 
Tentorium     cerebelli,    576,    581, 

582,  578 

Teres  major  in.,  380,  62,  65,  76, 
77,  110,  184,  185,  343, 
373,  381,  390 


Teres  major  in.,  action,  380 

blood  supply.  3-0 
ilisorlion.  3-n 
nerve  supply,  380 
origin.  380 

relations,  ::-n 

minor  in.,    380,    184,    185, 
341,  373,  381 

action.   3-'ll 
blood  supply,  3-n 
insertion.  3-0 
nerve  supply,  3-0 
origin.  3-o 
n-liii  ions,  3-0 
Tot,  Spence's,  .">.- 
Tlieca  of  llexor  tendons,  166 
Thecitis,  32,  168 
Thenar  eminence,  32 

muscles  forming,  171 
Third  cervical   n.,  posterior  divi- 
sion, 410 
cranial  n.,  591 
Thoracic  a..  85 

long,  53,  5*.  85 

anastomosis,  -5 
superior,  82,  76 

anastomosis.  s5 
intertransversales  m.,  407 
nerve,  external  anterior,  90, 

76,  87 
internal  anterior,  !)0,  76, 

87 
posterior  or  long,  92,  76, 

77,  87 
primary  division  of 

spinal.   410 

origin  of  spinal  u.,  361 
vertebra',  spines.  3111 
Thorax,    relations   of  viscera, 

363 

Thrombosis  of  lateral   sinus.    5-1 
Thumb,  amputation,  37,  :.'s  I 

structures  involved,  284 
sesamoid  bone,  37,  247 
Thyroid  v.,  middle.  509 

superior.  509 
Tic  douloureux,  564 
Tissue,  adipose,  of  axilla,  95 
areolar,  of  axilla,  95 

of  eyelids,  516 
Tophi,  529 

Torcular  Heropbili,  455,  583 
Trachelo-inastoid    m.,   401,   396. 

397 

action,  401 
blood  supply,  400 
insertion,  401 
nerve  supply,  401 
origin,  401 
relations,  401 

Tract,   motor,  of  spinal  cord,   de- 
generation in.  450 
olfactory.  554 
Tragieus  m.',  520.  527 
Ttagus.  524,  525 
Transversalis  colli  m..  400,  396, 

397,   509 
action,  400 
blood  supply,  400 
insertion,  400 
nerve  supply,  400 
origin,  400 
relations,  400 


INDEX. 


031 


Ti-ausverse   facial   a.,   508,    472, 
477,   484,  504,  542 
vein,  509 

lines  of  abdomen,  52 
.sinus,  590,  578,  579 
Transversns  auris  ni.,  529,  527 
Trapezium,  31 
Trapezius  in.,  372,  65,  373 
action,   372 
Wood  supply,  372 
insertion,  372 
nerve  supply,  372 
origin,   372 
relations,  372 
Trapezoid    liuamcnt,    221,    218, 

219 
Trauma  of  circumflex  n.,  124 

of  ulnar  u.,  123 
Treatment  of  anenrysins,  204 
Trephining  in  extra-dnral  hemor- 
rhage, 598 
Triangle  at  elbow,  130,  131 

contents,  130 
infra-clavicular,  deep,  73,  71 

dissection,  73 
superficial,  07,  70 
dissection,  07 
of  palm,  32 
of  Petit,  376,  52,  373 
suboccipital,  407,  406 
contents,  407 
formation,  407 
subscapnlar,  86,  390 
Tributaries  to  lateral  sinus,  584 
Triceps  m.,  ]H8,  65,  70,  76,  77, 
110,  184,  185,  381, 
390 

action,  192 
blood  supply,  192 
beads,  191 
insertion,  191 
nerve  supply,  192 
origin,  188 
relations,  191 
Trifaeial  n.,  592 

neuralgia,  562 
Trigeminal  neuralgia,  564 
Tripartite  m.,  388 
Trunk,  back,  351 

landmarks,  351 
Tubercle,  Darwin's,  527 
deltoid,  18 

of  Montgomery,  54,  55 
of  scaphoid,  31 
Tuberosity,    bicipital,  of  radius, 

28 
greater,  of  humerus,  27,  185 

fracture,  273 
lesser,  of  humerus.  27 
Tumors  of  mammary  gland,  58 
of  scalp,  451,  480 
of  spinal  canal,  449 
Twelfth  n.,  593,  579 
Tympanic  a.,  547,  546,  550 


IT. 

Ulna,  31 

centers  of  ossification,  209 
coronoid  process  of,  fracture. 

278 
development,  209 


I'lna.  dislocation,  25.) 

structures  involved,  255 
excision,  203 

structures  involved,  203 
fracture,  278 
olecranou  process  of,  fracture, 

278 

Ulnar  a.,   144.   Ill,   131,   135, 
140,  141,  145,  159, 
173,  177 
branches,  147 
course,  31 

guide  for  ligation,  134 
incision  for  ligation,  301 
ligation,  311 

collateral       circula- 
tion, 311 
structures  involved, 

311 
line,     144,     122,     176, 

30O 

relations,  147,  328,  329 
deflection,  17 
head  of  flexor  sublimis  digi- 

torum  m.,  134 

nerve,  91,  123,  151,  102,  76, 
77,     87,    110,    115, 
118,  128,  131,  136, 
140,  141,  159,  173, 
185,  194,   200,  381 
branches,  151,  102 
course,  38 

cutaneous  branches,  120 
dorsal,  190,  97, 

140,  141 
palmar,  97 

incision    for    stretching, 

301 

irritation,  314 
line,  312,  122,  300 
motor  point,  40 
operation      to      expose, 

316,  317 

relations,   123,   151,  162. 
316,  317,  321,  328, 
335 
stretching.  312,  313 

structures  involved, 

312,  313 
trauma,  123 

recurrent    a.,    anterior,    147, 
111,    140, 

141,  145 
anastomosis.  147 

posterior,   147,  111, 

140,     141, 

145,  200 

anastomosis.  147 

vein,  anterior,  126,  195,  100, 

128 

common,  100 
posterior,  195,  100,  110, 

128 

Ulno-carpal  ligaments,  237 
Upper    extremity,    amputations. 

279 

anterior  view,  40 
arteries,  ligation,  294 

lines,  300 
articulations,  17,  215 
bones,   development    of, 

266 
dissection,  47 


Upper  extremity,  divisions,  17 
joints,  17,  215 
landmarks,  17,  18 
movements,  17 
nerves,  stretching,  311 
posterior  view,  41 
surface  markings,  17,  18 


V. 

Vaginal  ligament  of  fingers,  167 
Vagus  n.,  593 

Varicose  aneurysm,  309,  295 
Vasa  aberrantia,  114 
Vasciilarity  of  face,  511 
Vein,  angular,  470,  509 
anterior  .jugular,   509 
maxillary,  551,  509 
temporal     diploic,     571, 

569 

auricular,  posterior,  509 
axillary,  80,  62,  71,  76,  77 
pressure  upon,  81 
relations,  310,  317 
wounds.  57.  80 
basilic,  104,  100,  110,  115, 

118,  128 
median,  103,  100,  110, 

128 

infusions  into,  104 
cephalic,  27.  103,  59,  70,  71, 
76,    77,     100,     110, 
128 

median,    103,   100,  128 
cerebral,  superior,  573 
cervical,  deep,  403,  509 
circumflex,   posterior.  341 
deep  cervical,  403,  509 

facial,  551 
external  jugular,  509 

line,  487 
facial,  470,   508.  477,  484, 

485,  509 

arterial  blood  in,  511 
communications,  511 
course,  511 
deep,  551 
disease,  511 
line,  487 
transverse.  509 
infra-orbital,  540 
innominate,  509 
intercostal,  425 
internal  jugular,  509 

maxillary,  551.  509 
jugular,  anterior,  509 
external,  5O9 
line,  487 
internal,  509 
posterior,  509 
lingual,  509 
maxillary,  anterior,  551,  509 

internal,  551,  509 
median,  126,  100,  128 

basilic,   103,   100,  110, 

128 

infusion  into,  104 
deep,  100,  128 
middle  temporal,  509 

thyroid,  509 
occipital,  509 


632 


INDEX. 


Vein,  occipital  diploie.  571,  569 
orl)itul,  509 
radial,  126,   l!ir>,  100,  101, 

128,  339 
subckivian,  509 
submental,  509 
snhscapnlar,   343 
snperlicial     temporal.     484, 

509 

superior  thyroid,  509 
supra-orbital,  509 
supra-scapular.  509 
temporal     diploic,    anterior, 

571,  569 
middle.  509 
superficial,     484,     477, 

509 
temporo-maxillarv,        485, 

509 
thyroid,  middle,  509 

superior.  509 
transversalis  colli.  509 
transverse  facial,  509 
nluar,      anterior,      12(i,    195, 

1OO,  128 
common,  100 
posterior,       195,       100 

110,  128 
vertebral,  509 
Veins,  diploic,  568,  569 
dorsi-spiual.   425 
entrance  of  septic  matter  into, 

81 
frontal,   571,  509 

diploic,  571,  569 
fronto-sphenoid,  571,  569 
libation,  HI 
nieclulli-spinal,  427 
meningeal,  599 
meningo-rachidean,  427,  425 
of  arm,   103,  100 
of  eyelids.  519 
of  /'ace,  509 
of  forearm,  100,  101 
of  Galen,  578 
of  hand,  195,  101 


Veins  of  head,  509 

of  mammary  gland,  57 

of  neck,  509 

of  ptci  yuo-maxillary  region, 

551 

of  scalp.  470,  509 
of  spinal  canal.  427 

cord,  145 

of  upper  extremity,  28 
pterygoid  plexus,  551 
spinal,  425 
Vena    basis    vertebrie.    127,    413, 

425 

comes  of  radial  a..   12- 
Venn-  comites  of  aeromio-t  horacic 

a..  85 
of  braeliial   a.,    22,   77, 

113 

Venesection,  104 
Vertebra,  dislocations,  424 
fractures,  424,  449 
spine  of  seventh  cervical.  361 
of  sixth  cervical,  l!56 
of  third  sacral,  361 
Vertebra.1,  abscess  in  caries,  '.}'>!> 
cervical,  abscess,  356 

diseases.  o.~>(> 
dorsal,  abscess,  356 

caries,  :!5<i 

ligaments  uniting  bodies,  412 
lumbar,  abscess,  356 
caries,  :!5(i 
spines,  361 
spines,  352,  356 
thoracic,  spines,  361 
Vertebral  aponeurosis,  394 
artery,  408,  406 
column.  412 

ligaments,  412 
fascia,  394,  373,  396 
ligaments,  417 
vein,  509 
Vidian  a.,  548,  546 

nerve,  5G2.  554,   559 
Vincula  aecessoria,  168 
VincuHe  of  hand,  206 


Viscera   of   abdomen,     relations. 

363 
of  thorax,  relations,  363 


W. 

Walls  of  axilla,  (il,  79 
Wardrop's    method     of     treating 

anenrysm,  297,  295 
Wilde's  incision.    '. 
Winged  scapula,  222,  ::<i2 
Wounds  of  axillary  vein.  57,  -n 

of  deep  palmar  arch.  1-0 

of  face,  511 

of  longitudinal   sinus,   supe- 
rior, 583 

of  middle  meningeal   a..  ">!>- 

of  palmar  arches,   I -it 

of  parotid  gland.  522 

of  scalp,.  4(i(i,  480- 
Wrisberg,  ganglion,  200 

nerve,  91,  103,  124 
Wrist,  31 

abscess.  32 

furrows,  31 

level,    31 

Wrist-drop,  125.  277 
Wrist-joint.       I'iile    Radio-carpal 
Joint. 


/ygomatic  arch,  460 
fossa,  557 

contents,  557 

Zygomaticus  major  m.,  500,  491 
action,  501 
insertion,  500 
nerve  supply,  501 
origin,  500 
minor  in.,  501,  491 
action,  501 
insertion,  501 
nerve  supply,  501 
origin,  501 


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